part 2 is definitely more enjoyable. this one is a bit boring. if you dont think into consideration the impossible badge, the game is pretty much a walk in the park. funny how a stage 5 boss bullet is so much more harder to evade than the level 10 boss.
i think the game ends when u enter the palace ... because i couldnt find anywhere else to go after that ... anyway, try to get "Z" on your starting location. once you got that, ur almost invincible throughout the whole game.
got my badge. last boss is insane. just place your cursor over his left eye and keep shooting the same spot each time he lands in between level intervals.