GAME BOOMERS hints, cheats, and walkthroughs Castle Infinity - Cheat
If you hold control and jump, if the floor isn't directly over null space, (i.e. Going through the floor there will take you to beyond the beyond.) then you'll go right through the floor.
An exception would be in your room looking at your points. If you do the trick here, you'll go down into the little tab and be able to jump off and into beyond the beyond.