On the title screen, type "328GTS" and you'll see the message {CHEAT NOW ON STEVE}. Press the right mouse button during play to skip levels.
00- "MMMRHM" | 13- "CMMRHQ"
01- "AMMRHA" | 14- "IAMRHB"
02- "HMMRHH" | 15- "RAMRHF"
03- "VMMRHV" | 16- "MHMWHM"
04- "PMMRHP" | 17- "AHMWHA"
05- "GMMRHG" | 18- "HMMWHJ"
06- "IMMRHI" | 19- "VHMWHV"
07- "RMMRHR" | 20- "PHMWHP"
08- "MAMRHW" | 21- "GHMWHG"
09- "AMMRHN" | 22- "IHMWHI"
10- "HAMRHZ" | 23- "RHMWHR"
11- "VAMRHT" | 24- "MVMWHM"
12- "HMMWHH" | 25- "AVMWHN"