To gain unlimited CP in level 2, get a plasma gun (H) and save it until the second mini-Boss. Go to the right side, charge the plasma gun, then crouch and kill all of the alligators. While doing this, shoot the gun horizontally at all bombs that the helicopter drops to increase your combo. Fire vertically when a bomb falls overhead. Do not shoot the helicopter. You can build a 60 combo and get about 50 million CP before the combo meter stops. When you start earning negative points, intentionally die. Restart the level and repeat as desired.