Cheat Mode
Here's a great cheat for Slap Fight. Insert a credit and select 1 player. When you begin the level, just sit there - don't kill anything. Let your player be destroyed. When you begin again, you'll have all weapons and powerups! If you don't fire at all, but dodge your way through the enemy shots as long as possible, you'll get a big bonus and start your next life just before the second big boss. You have to get as far as the ring shaped pool to get this.