A few boss fight tips
Bosses often come with a couple of grunts. Since these grunts die much faster than the boss, it might be a good idea to kill them off before the boss. When the multi-target attacks are available (such as Aschen's first all-enemy attack), they become good openers for these battles. Both the boss(es) and the grunts are hurt, the grunts moreso.
Pretty straight forward, just keep going up. You can smash rocks by pressing A. If you find a locked door, check the paths on the sides, one of them will have a computer you can operate to open the door.
Eventually, you'll find Kaguya in one of these rooms, and you'll come to a door with a "3" mark which you can't open yet. Ignore it and search the path on the left for a door that leads to your first boss fight. After you're done, you'll exit the dungeon automatically and end up at your base/ship/whatever that thing is.
Besides your usual options (Rest, Save, Shop, etc.) non-dungeon areas also often have an additional option that let's you talk to someone or go somewhere within that area, try this in every place you visit to progress the story. In this particular case, I recall you can talk to someone, I'm not sure if it makes a difference or not, but I suggest you do so. Once you're done, rest/save if you want and head out.
Walk a bit to the north, then east, you'll see a town.
An event triggers as soon as you enter, I think there's someone you can talk to here as well, so try it. Anyway, once you're done, leave.
Walk a bit to the east then north and you'll see the next dungeon, it looks like a spaceship on the outside. Enter it.
Here you can climb ladders by holding the A button and moving with the pad, if you let go of the A button you'll fall instantly. Your goal is to reach the top to turn on the elevator you saw at the bottom level. Once you do so, keep walking to the right into what looks like an abandoned lab. Eventually you'll met T-elos, follow her to a room with a lonely console, turn it on for a boss fight. Once you're done with that, leave the dungeon manually (which is easy now, thanks to the elevator).
Head to the north and west of the dungeon and you'll see something in the ocean, this is called a "Cross-gate" and it's used to travel through the game's different worlds, get near it and check it with the A button to go through it. You'll end up in "Kagura Amahara". In this new map, keep walking until you reach the nearby town.
When you get here, there will be some dialog and Kaguya will leave your party. Then pick the second-to-last option in the menu to go to some sort of shrine within the town, head north until you see Kaguya, an event occurs and you get Kaguya back. Rest, shop and save if you want, then head out.
Head north until a path split, then head down and east, you'll eventually see the dungeon (looks like a cave/rock castle on the outside).
In the first room there's a save point and a statue that fully recovers your HP/SP, heal and save if you want, then walk all the way north and then right, you'll see a door in the wall leading up and a path to the right, take the door, you'll come out in a room with many crystals (which you can't break at this point), walk left and make it to the bottom level, then look for a path on the left. An event will occur here and you'll get Suzuka. Head back a to the previous room and walk north (or go back to the beginning and save/heal first, since the next boss is hard), then fight the boss. Once you're done leave the dungeon (or explore the remaining parts for some items, if you wish).
Head west of the dungeon and back to the path split. On that split, head north and west until you reach a second town.
Japanese Town 2
When you enter here, there will be an event. After it's done, go talk to Otone (white clothed female ninja) for another event, then exit the town
Head left into the nearby cross-gate and enter it to reach "Elfe Tale". The path here is pretty straight forward, so just follow it. Eventually you'll see a castle town full of red crystals and an event happens. A bunch of red crystals will pop up before you, preventing you from going back to the cross-gate, so just go into the nearby castle.
Event happens. There's two exits, one for the right side and one for the left, use the left one.
Follow the path that leads to the dungeon (that castle with the clock).
Dungeon 4 (Poker Dungeon)
As soon as you enter, you'll notice a blocked door and two kinds of statues : Clown and bunny. Clown ones can be broken easily with the A button. For the bunny ones, walk next to their "handle", then hold "Y" and push (not pull) towards the handle. 3 of them should break by doing this, the remaining one will stop next to a platform, climb that platform and destroy it yourself from there. Once you've broken all bunny statues the door should open.
In the next room, there's a bunch of clown statues, and a bunny one in the middle of them, you need to make your way to the bunny one, breaking any small statues in your way, be prepared though, as most of them will trigger a random battle when broken. Once you make it to the bunny statue, break it for a boss battle.
Once you beat the boss, stand on the floor where she was and you will fall down to another area, keep going through this area until you're in a room with a save point. In this room, go through the only available path and you'll meet Reiji and Xiaomu, and then will have to fight them, they will join you after the fight. Now take notice of the 3 ice columns on the room, from left to right : Push the 1st one straight down into the hole, then break the small rock directly below the 2nd column and push the 2nd column into the hole as well, now exit and enter the room so the rock you broke appears again. Push the 3rd column towards this rock, then down into the hole. Go back to the bottom floor and touch the path of ice, if you did it right, the columns will prevent you from falling and will form a bridge for you. Follow this path into a new room with a spiral path and a boss fight at the end of it. After that, you're done with the dungeon, so leave and go back to "Castle Town".
Event happens as soon as you come back, after that take the exit to the right.
Head to the east towards the nearby dungeon, it looks like a dark castle on the outside.
Straight forward, just go through the only available path smashing any rocks that get in your way, and be careful of the poisonous tiles on the floor. You'll get go a big room full of rocks, take the left path for an item or the right path to make it to the north of the area, where a boss awaits you. After that, push the statues into place to clear the way. You can take the left path for a shortcut back to the beginning of the dungeon, or you can take the right path for another boss. Once you beat the boss, keep walking and you'll reach the exit.
Follow the yellow brick road and it will lead you to some sort of millitary-base-looking structure, but you can't enter now, so just ignore it and walk down and to the right a bit to find another town.
Castle Town 2
Event triggers as soon as you enter, then leave.
The military-base thing should be accessible now, enter it.
Ignore the ladder on the center and head to the left, follow the path from there which is pretty straightforward and leads to a boss fight. Once you beat the boss, activate the nearby button and it will lower the spikes granting you a shortcut back to the beginning of the dungeon and access to another button. So go back there, save if you want, then activate the now accessible button to open the door. In this new room head to the top for another boss fight.
After this, keep walking there will be two paths, you can go either way, but I suggest you go right first, so turn right and keep walking until you get to a boss. After you beat it, walk down and activate the two switches to lower the spikes that were around where the boss was (you can also open a door on the bottom part for a shortcut to a previous area). Explore the area completely, you need to collect 4 key items to proceed, 3 of them (IIRC) are in this room, so grab them (you'll know it's a key item because the name is in green). You'll also find KOS-MOS in here. Once you're done exploring the room, leave and take the left path this time. The left area is exactly the same, there will be a boss and switches to turn down afterwards, you'll find the remaining key item here. Once you have all 4 key-items, head back to the room where you fought the catgirl boss earlier. Notice those 4 pillars? You have to check them directly from below (not side or above) to place the key items in there, so place all 4 key items and the elevator will activate, take it.
In this new room, there's a puzzle. You'll see a door and a mirror and two statues on each side. Talk to either mirror twice, now you have to turn the statues in a certain pattern (to turn a statue, check it and select the position from the menu). The patterns are :
Left Side- Yellow faces right Red faces left
Right Side- Green faces left Yellow faces left
Left Side- Red facing left Green facing right
Right Side- (left)Yellow facing right (right)Yellow facing forward
You can thank namek jin8 for figuring that.
After you've set up the statues the correct way, you must talk to the mirror and pick the 3rd option to acknowledge your answer. Do this for both sides and the door will open.
After the puzzle, it's boss time again. Beat the boss and you'll get the ability to break blue crystals, and the boss herself will sell you stuff if you talk to her. Leave the dungeon.
Head south and west towards the big door and check it. Nothing will happen to the gate itself, but that cross-gate near "Castle Town 2" will open, so go there and use it.
You'll come out back in Lost Herencia. Head south and you'll see your ship and the 1st dungeon, go to your base.
Event happens, then leave and go to the 1st dungeon.
Dungeon 1 (Revisited)
Head to where you found your first boss (walk north all the way until 2nd save point, then turn left and go through the door), for a boss fight. After you're done with it, walk through the door, which you should be able to open now. Keep walking through this new area and you'll get to a BIG room which has these "pod" things around. You can't leave this room once you enter, so check all pods (I think there's 8 of them), then try to leave, but as you do so, a boss will appear on the top part of the room, walk there and fight it. Once you beat it, you'll exit the dungeon automatically and you'll be back in your base.
Event happens. Also, now Harken can use the "Gespent Kick" skill and you can use mech support.
Head to "Kagura Amahara" through the cross-gate, then head to Dungeon 3.
Dungeon 3 (Revisited)
Head to where you fought the boss earlier, now you can break those blue crystals and open the door. What follows is a pretty straight forward path with 2 boss fights along the way. You can go back and save between fights, but you can only leave the dungeon itself before you fight the 2nd boss (in case you need to re-stock on items). The 2nd boss fight will be your first one that forces a certain character to the front, in this case, Suzuka; Whenever this happens the game will automatically place the forced character on the 1st slot in the front and prompt you to reorganize your formation. Be careful though, as you can't change equipment in this screen, if you need to do so, do it BEFORE the fight. Anyway, once you beat both bosses, keep going and you'll find a shortcut back to the beginning, save, then head to the exit, but as you try to leave, there will be another boss fight (hope you didn't waste too much items on the previous boss). After that, you can leave.
Head back to your base in "Lost Herencia".
Event happens, afterwards pick the second-to-last option for another event. Your base will move towards the nearby cross-gate and back into "Elfe Tale", it'll also get rid of that door we couldn't open before. When the event is done, leave the ship.
Walk to the bay on the left for an event with the pirates, then walk up to see a giant cat-tank thing get close to your base. Go back to the base.
Stock on items if you want, because you won't be able to leave the following dungeon until the end. When you're done, pick the 3rd option, watch the cool scene, when it ends you'll be in a new dungeon.
No puzzles or anything here, very straightforward. There are two boss fights with a save point between them. The first boss fight is against the Egyptian-ish cat and a buff guy in red clothing with a horned skull for a head, along with two grunts. The skull guy doesn't deal hideous amounts of damage, the cat is more dangerous. The cat also seems to reduce the damage he takes and evade quite a few attacks, so it might be a good idea to leave him for last. The grunts go down pretty fast as far as boss grunts go. The second boss is the pink-haired white-robed cat girl (the one with the coin tossing attack), along with two grunts and a new friend who looks like a buff Fox. They aren't as tough as the first fight, but beware of the multi-attack of the Fox guy; it is capable of stunning.
Giant Cat Tank
You'll be inside this thing now and your base will return to it's original place in "Lost Herencia". This place works like a regular town, so do the usual. When you're ready, one of the options will take you further into the desert to a pyramid dungeon. Notice that unlike the previous dungeon, you can leave this one and go back to the Giant Cat (or the world map, even) at any time.
First part is straight forward, until you reach the little puzzle. You will reach a room with some kind of face thing in the center of the room, as soon as you enter you'll see a scene in which a red and blue orbs, along with a bunch of gray orbs go into the 6 coffins around the room. You must pay attention to the location of the red and blue orbs, ignore the gray ones. There's two doors on the top part of the room, one on each side, go there and you'll see a bunch of pillars, push them down the holes to break the corresponding coffin, ideally, you will want to break only the correct one. Now go back and you'll have to fight each orb you liberated (common random battle), once you've "defeated" both the red and blue orbs, the face breaks revealing a door, but WHOOPS, not too fast, you better save first because as soon as you try to go through a boss will stop you.
Keep walking through the new room and be careful with the flames (no big deal if you touch them though, just lose a little HP), you'll reach another save point. Save, then walk to the right and you'll notice some of the gargoyles in the wall have glowing eyes, press A between them to destroy the wall and make way, left one leads to boss, right one leads to item. After the boss is gone, there's 2 more breakable walls, left one has item, right one goes further into the dungeon. In either case, you'll need to push the small pyramids into place.
You'll be back at the begging of the dungeon, except you're on the top part now. There's a few pillars around here which you can push, doing so not only grants you a shortcut but also a path to continue advancing, so push them. After some walking and stairs, you'll reach the 3rd and last boss of this dungeon, after you beat her, leave the dungeon.
Giant Cat Tank
An event triggers after you get back, after that, go back to the world map (I mean, outside the dessert).
Walk left for another event with the pirates, they'll let you borrow their ship, it seems. The places the captain shows you are the ones where you can go by selecting the proper option in the menu, not that it matters now because we're going somewhere else.
Like the Giant Cat Tank, this place works like a town. Pick the 5th option when you're ready (the one in brackets), the ship will go through the nearby cross-gate and into an underwater dungeon.
Go left and deeper into the dungeon until you reach the next room, you might have to destroy a crystal on your way which will make a block fall. In this next room, head all the way south, then turn left, then north and you'll see a wall with some vines. You can move through this the same way you did with the ladders in Dungeon 2, it leads to some items, if you wanna proceed with the dungeon just keep walking right. Now you'll see 4 crystals on the left side (forming a square) and a single crystal on the right side, next to the block you released earlier in the beginning. Destroy the bottom right crystal on the left group first, then the one on the right side next to the block, this should place the block where the crystal was, now break the crystal directly above the block to push it downwards and make a path (if you mess up, just enter the nearby door and exit to reset).
Now walk left and destroy the crystal to push another block into place, then head right to create a shortcut back to this room's save point, then head left to where the block fell, follow the path and you'll see a vine that goes down and into the next room, take it.
As soon as you enter you'll see a save point, SAVE, what follows are 3 consecutive boss fights, you can go back and save between them. After the last one, event happens and you'll be back into the pirate ship.
Do the usual, when you're ready head back to Dungeon 6
Dungeon 6 (Revisited)
Head to where you fought Dorothy (you know, the last boss of this dungeon). An event happens and now you have the ability to break red crystals, leave the dungeon.
Remember those red crystals that popped up when we first visited this world? You can break them now, giving you access to that giant tree/plant thing. There's actually a cross-gate at the top of it, and you need to go trough there, be warned though, that once you go through it you won't be able to come back for a while, so take the chance to stock on anything you may need. When you're ready, enter it.
Technically this should be "World Map", not dungeon, but the whole thing works like one big dungeon, so I will refer to it as such.
Most of the paths are closed at the moment, so the path to follow is totally straight forward. Keep walking until you see a building, enter it, you can use the statue here to heal and there's also a save point. When you're ready, head upstairs for a boss fight with Dorothy. After you beat her, you can buy stuff from her (same stuff she sells at her castle). Go right and downstairs, you'll be on the other side of the 1st floor, push the two coffins into place and you'll get a shortcut and also activate a warp. You can take the warp to an area with a treasure chest if you want. Anyways, get out to the right and keep walking until you see another building.
In this new building, the catgirl you've fought before will sell you recovery items, then there's another save point. Once again, head upstairs for another boss fight, then walk left and downstairs, and push the coffins like in the previous building. Don't take the warp as there's nothing you can do in that area right now. Exit to the left.
Soon you'll see the castle, but it's closed right now, so take the left path instead for a LONG walk around the castle and to a green structure and enter it, inside a boss fight awaits you and Aschen will be forced in the front line for this fight. After you're done with that, you'll get the castle's key and the red blocks below will disappear, so walk down and back to the castle and enter it.
In the castle, walk north and you'll soon see a save point and path split, take the left path, then walk north and take the right passage just before the statue (you can break the statue for a random battle and a path that leads to an item, if you want). In this area, you need to break some pillars to uncover warps. Take the only one available, then the right one (left leads to item) and turn on the switch there, then go back to the path split at the beginning. Now take the right path, which is exactly the same as the left one, except breaking the statue here does nothing (no random battle, no extra path). Once you've activated the switch on both the left and right paths, head back to the split and take the middle path, then just keep walking north for another boss battle, with that homosexual cat from before. Once you're done with that, break the crystal pillars to open the door and keep walking north.
The next room is basically a straight path with multiple path splits and lots of statues, some of them have items, some not. Explore if you want, but be careful as breaking some statues will initiate random battles. Take left on the second-to-last split to advance into a new room (Also, there's an accessory on the path to the right which will give you a VERY nice SP bonus, ideal for whatever character you use to spam seishin). In this new room, break all the crystal pillars at the start to reveal a save point, then head right and break all the pillars to reveal an elevator, take it. Now break the crystal pillars to reveal a warp, take it and head north for the 5th and last boss fight of this area.
After you're done, you'll get Card Key 3, also those yellow blocks on the area will disappear. If you take the warp in the 2nd building which I told you not to take before, you can reach an area with a mysterious treasure chest surrounded by smoke, but it's unreachable now, and it will remain so until New Game+, so don't bother with it. Anyway, we're done here, walk back to the beginning of the dungeon and take the cross-gate (which is working again) to go back to "Elfe Tale".
Head back to "Lost Herencia" (you can use the pirate ship and pick one of the options to get faster to the cross-gate) and go to your base for an event, afterwards head to the 1st dungeon once again.
Dungeon 1 (Revisited again)
Just keep walking north and that's it. On the way you'll go past the door with the "3" mark (should be able to open it now) and you'll have to operate a console to reveal a bridge, then check the broken pod thing in the middle for an event and then a boss fight, in which Harken will be forced into the front. After you're done, leave.
Back to your base for another event, then head back to "Kagura Amahara" and go visit "Japanese Town".
Japanese Town (Revisited)
As you enter, there will be an event. Then pick the second-to-last option in the menu to go where Kaguya was earlier in the game, except the door at the top can be opened now, extending the area into a new dungeon.
Keep walking till you see a save point at a path split and take the south path to head into the next room (north leads to treasure chest you saw at the beginning). In this new room keep walking until you get to a boss fight, then walk left and go into the next room. Now walk up and to the left and you'll see some vines on the wall, climb them and follow the path into the next room. In this new room there's a save point and another path split, take the right one (left leads to item). You should be outside now, walk left and soon you'll see a green vine within reach and some sort of black roots that go straight up. The vine leads to a tresure chest you saw earlier and couldn't reach, but it's a long and frustrating path, the roots lead to the top of the dungeon and to another boss battle, in which Kaguya will be forced to the front. After that, you'll leave the dungeon automatically. A lot of events will happen, when that ends, you'll be back in "Futuristic Town" I think, anyways, leave when you're ready.
Back to "Base" for an event, then head back to Dungeon 2
Dungeon 2 (Revisited)
Head towards the last part of the dungeon. Remember that door where T-elos showed up before, a few rooms before the boss fight? You should be able to open it now, do so and go further into the dungeon until you reach a save point. There's an elevator here but it's not working right now, so head right and descend into the lower level, then head left and into the door, but whoops, as soon as you try to enter a boss fight ensues. After you deal with that, go through the door and activate the switch here to return power to the elevator, then go back and use it.
After you take the elevator, head right until you reach a big room with a huge machine in the center. Ignore the machine for now and keep walking right till you see a console with a red screen, activate it and an elevator will appear in the hallway before this room, so go back and take the elevator, then activate the two switches here, then go back to the room with the huge machine and prepare for a boss fight, both Reiji and KOS-MOS will be forced to the front for this battle. After that, check the machine, you'll have to tap the A button repeatedly to power it up, opening a portal to the final dungeon of the game. You'll leave the dungeon automatically after this.
This is your last chance to save, as you can't go back once you enter the final dungeon. Go buy stuff and do anything else you might need to do. When you're ready, save and head back to your base.
Event happens, then pick the second-to-last option in the menu to go to the final dungeon.
No random battles, no save points, 3 consecutive boss fights, straight forward area. As there's no save point, losing to any of the bosses means you'll have to fight them all over again, so be careful. Fortunately, that annoying catgirl is here, and you can go visit her in between each fight, she sells recovery items AND heals you (for FREE!). You probably have a lot of unspent money, so go wild, buy and spent as many items as you need, specially those that raise the F-Gauge.
Congratulations, you just finished the game. After the credits, the game prompts you to save for New Game+, save in an empty slot.
Loading that save will start the game from the beginning, but you get to keep all your items (including equipment and such), time you've played, and max attack/max hit record. Seems like you can also access that mysterious treasure chest in Dungeon 10 for an extra hard boss fight that rewards you with the game's strongest weapon, ATK-wise. Oh yeah, a new option will also popup in the "Game" menu with which you can listen to the game's many BGMs.