Press W to pause the game! enter following codes:

CUBICNATUREI ( For Infinite Lives )
CUBICNATUREC ( For Choosing Rooms )

Press Shift to resume the game.
Room codes have to be entered while
game is active, in which 0 is always the activator.
Example : hold 14 pressed and then press 0 and you will be teleported to "On a Branch Over the Drive"
Note: Not all codes work in emulation, all these codes were tested on a real machine though. 6 digit Room codes like 124560 won't work, while 5 digit room codes like 14560 will work in an emulator like openMSX.

Here's a list of all room codes including the 0 as activator!