I just beat the first boss and I'm fucking loving this game... much better than 3, combat feels so awesome, and it's addicting with the battle bonuses and attempting some of the battle trophies. Yeah, the environments are low-polygon and blocky, but the lack of much load time, palettes used and the texture detail more than make up for that. Then again I don't give a fuck about graphics in games.
Bebpo - after chipping off enough of the first boss's 'shell', you'll see a glowing blue spot on its side. Target it and you can do like 50-100hp of damage. Edge and Reimi were around level 7 when I beat it.