>>6
Schwill is correct. If you want the Spur, which is the strongest gun in the game in terms of sheer power (and due to the fact that you can charge it up to max level by holding the 'fire' button down, it doesn't use Stars like the other weapons).
Also, if you want to reach "Hell" the secret, EVIL as f--k level at game's end, one of the requirements is to SAVE CURLY. EVERY TIME.
Also, you MUST NOT talk to Booster in the Labyrinth. At some point there is going to be a HUGE PIT that you must jump over. If you look closely, there will be a red mark on the floor. If you jump at exactly that point, you will make it. If not, reload and try again.
This Is HELL:
http://www.youtube.com/watch?v=P3K48x3hx94