Level skip
----------------
At the options screen, type "getvonmaxguy" and press [F1]. The game will automatically start. 
At any point during gameplay, you can press [F1] to advance to the next level.

Level select
Type "rovena" and press Done at the options screen. The game will load up the level select screen with all levels unlocked.

Have tested using first cheat, all levels and disks loaded correctly. 