CHEATS
Pause game by 'ESC' (pop up sign with cow's skull) and the type one of these (while holding the shift or CASP_LOCK on!):
"THEMAGNIFICENTONE"
invulnerability
"MYNAMEISNEXT"
go to the next level
"ONCEUPONATIMEONTHENORTHPOLE"
Christmas level bonus
"YOUNGGUNS"
no comment ;)