Low G Man: The Low Gravity Man Cheats

Get to the walker in Chapter 1, Scene 2, freeze it and kill the driver to get in. Then move a few steps to the left and use the Walker's special jump. You'll reach the top of the screen, at which time you will see a ledge. You'll find the door to the warp on this ledge.

In level 4-1 (The Tower), go to the very bottom left corner of the screen. While there, jump up. You should be taken to a room where you get tons of power ups!