Click on the computer to get HACKS. S for the shop, R to do a cool thing, T to start rapidly changing colors (this looks really cool on the second computer), G to make it bigger, hold F to change colors and let go once you've found the color you like, D to multiply, E to reset all weird graphical effects, and SPACE to do weird and horrible sound. When you get to the MEGA COMPUTER press H and enter in MAN.
Press W for world record.