Boss Guide

The difficulty scale goes from Easy, Medium, Tricky and Hard. Also, the ghost in Neotokio is optional to beat.

Four Red Huballs
Location Difficulty HP
Tower 1 Easy 11 HP each
Tactics
No real tactic. Just kill them.
Three Cadets
Location Difficulty HP
Tower 2 Easy 3 hits
Tactics
Just try and hit the real cadet. It's usually the one behind you.
Three High Cadets
Location Difficulty HP
Tower 4 Easy 20
Tactics
Just kill them.
Dancing Huball Troupe
Location Difficulty HP
Tower 4 Easy ?
Tactics
Learn their pattern and hit the yellow huball. Now kill it. Repeat until all has been defeated.
Shadow Keeper
Location Difficulty HP
Tower 5 Tricky ?
Tactics
This boss is the first "real" boss you come across. First, he'll start out with shooting laser beams on you. Block those laserbeams and eventually he'll try to hit you with his claws. Whack on them using the rusher attack. After a while one of his claws will break, and the other one will be faster than before. Destroy that claw too and he'll slowly retreat until he hits the further side of the wall. Now he will change his attack pattern. He still shoots laserbeams, but now he'll also use his tail. Go for the mouth and eventually you will destroy it. The rest is a piece of cake. Keep going for his head and he'll soon be gone.
Parasite
Location Difficulty HP
Ra Tree Medium N/A
Tactics
First this guy appears as a snake in the big hole, and clawlike things appears in the six holes on the sides. Whack the claws until the snake dissapears. Now Parasite changes attackpattern. The snake goes between the holes, and a big (and ugly) eye shows up. From time to time the eye pops out of the hole, and every now and then it goes inside the hole to throw out those clawlike things. Destroy those claws and the eye will pop out again. Just hit the eye with the rushing-attack, and he shouldn't be much of a problem. On a sidenote, you can level up good on this boss. See the secrets section for more info.
Dark Twins
Location Difficulty HP
Grecliff Medium ?
Tactics
This battle is high up, so DO NOT fall down. If you do, you have to start the battle all over again. First there is a green bird, and he has got three types of attacks: He shoots flaming feathers on you, dives at you and makes a whirlwind which can blow you of the edge. Simply whack him whenever he gets close and he'll eventually call his buddy the brown bird (ain't he a coward? ;)). The brown bird drops bird doo on you while the green one continiues doing what he did before. Hit the green one a few more times and you'll win.
Stormkeeper
Location Difficulty HP
Zue Medium ?
Tactics
This one starts out as a skeleton. It has two attacks: it spits green flames on you and it throws its arms at you. Avoid the flames and when it throws its arms at hit it in its stomach. Then back off. Repeat until it you, Strike it. Repeat until it falls apart. Now it changes shape, and both you and it falls down. It still fire at you, but now it throws rocks at you, as well. Avoid the flames and hit it when It gets close. Just keep doing it that way and you will destroy him eventually.
Mud doll
Location Difficulty HP
Canyon Easy N/A
Tactics
Block his rocks, when he stops, pick up the rock under Leim and throw it on him. Repeat until defeated.
Dark Morph
Location Difficulty HP
Eklemata Tricky N/A
Tactics
Okay, this guy is a bit hard. First, make sure you're equiped with Neo's fang, since it makes wonder against this boss. First he starts of as a Yeti. All he does is to throw out some crystals and create a blizzard. Avoid the blizzard by standing at a corner and walk in the opposite direction the wind is blowing. Next, he'll transform into a wizzard with the Agahnim syndrom, i e to hurt him you have to hit those orbs he is firing at you back on him. Now it`s time for the real battle. The Dark morph transforms into his old self again, a dark humanoid. He'll go around the area at high speed, so hit him whenever you get the chance. When you hit him, he`ll transform into bats. Run around and whenever they get near, do the runattack. Hopefully you'll get past 'em. Wait until they transforms into Dark morph again, then hit him again. Repeat until dead.
Soul Knight
Location Difficulty HP
Sylvain Easy 172
Tactics
Just kill him. It can be a slightly hard battle at low levels (Level 17-19 that is), if that is the case fry him with a firering.
4 Dolls
Location Difficulty HP
Sylvain Easy 3 hits
Tactics
Stand still. When the dolls stop, hit the one behind you. Repeat 3 times and prepare to face...
Bloody Mary
Location Difficulty HP
Sylvain Hard 350
Tactics
Tough one. Do the Slicer attack to inflict damage without taking any yourself, and if you have Elecrings, use them. Equip yourself with the Lightpike for maximum damage. At low levels she is a real pain in the a**, so make sure to be level 25+.
Four Ghosts
Location Difficulty HP
Ship to Freedom Easy 3 hits
Tactics
These ghosts can't be hurt when they are spinning, so don't even try. Apart from that, try to hit the real Ghost. After three hits the ghosts fade away.
Big Fish
Location Difficulty HP
Mermaid Tower Easy ?
Tactics
Have your back turned to it and whack it whenever it gets near. Look out for those green fishes, as they bounce you away from it. It should go down fairly quickly.
Ghost
Location Difficulty HP
Neotokio Easy ?
Tactics
No real tactic, just hit it when you get the chance. Sooner or later it'll fade away.
Hitoderon
Location Difficulty HP
Great Lakes Cavern Medium ?
Tactics
You don't have to worry about Gossie (the big dragon), since he won't hurt you. The three starfishes are a little hard to beat, though. First, kill those starfishes that jump up on that piece of wood you are standing on. The last one is a different matter. Walk under him, and when he falls, step aside and then quickly attack him. If the starfish attaches itself to your head, wait until the Gossie burns it off.
Security Robot
Location Difficulty HP
Beruga's Lab Hard ?
Tactics
Make sure you have a whole lot of Mbulbs and Lbulbs. Also level up untill you're at level 28 or higher. Some people claim that the geostaff is the best weapon to use against this guy, but I'm not 100% sure on that. Can't hurt to try though. Anyways, when you first enter this boss shoots missiles on you, and after that it uses one of its arms to make one of three attacks. Avoid the missiles by running around as mad. The whiplash attack can be blocked, but the other attacks can't, so you just have to avoid 'em. Once you've avoided the missiles, hit one of the three legs until it gets destroyed (you'll see when one leg is destroyed when small explosions surround it). after you've destroyed its three legs, it breaks apart and turn into some smaller machines. These ones are easily killed with the slider attack.
Dark Gaia
Location Difficulty HP
Gaia Stone Tricky ?
Tactics
This is the final boss you come across. He's got two shapes, and the second shape is described under this one. The first shape is a big statue made of crystal. He has got several attacks that needs avoiding. The attacks are as follows:
Gaia's rage - walk around to avoid getting hit.
Magirocks - Dark gaia throws out magirocks, which explodes after awhile.
Sonic boom - Stand on the right or left edge of the platform.
Light orb - This is the only thing that can hurt Dark gaia at first. Stand on the right/left edge of the platform and hit the orb as soon as you get the chance. When Dark gaia starts getting near you with his body curled into a ball, wait until he stops, then hit him as much as you can. Repeat until dead.
Dark Gaia (Final)
Location Difficulty HP
Gaia Stone Tricky 1000
Tactics
For this boss, make sure you're on level 32 or higher, or else you're probably grinded meat. Also, equip the HeroPike and HeroArmr if you haven't already. He's got two attacks, one which he shoots sparks on you and one where he uses a lightningbeam which eats up your energy. As soon as he uses his beam, press the R/L-button to block. That way you only loose 1 to 4 hp instead of half of it each time it hits you. Just whack loose on him with everything you've got whenever you can and he`ll soon be defeated. Phew. Sit back and enyoy the incredible ending. =)