Cheats:
On the help menu choose "About" hold SHIFT and click the black part of Bug's right eye. Type "babyseals" in the box that appears, click "WOW". Now select the blank menu that has appeared next to help to access the following.

Code Effect:
Invincibility - Bug passes through enemies
Flying Bug - Press Y to fly
Hitpoints - Take no damage
Level Skip - Use Crouch + UP for next level, Crouch + Down for previous