Going into the 5th dimension (rotating the room structure using the mouse) for a special level would be interesting too
i was actually planning on having the 5th and 6th dimension involved at one point, but it wasn't feasible with the time limit. it would basically be a grid of grids, sort of like the switch from 2d to 3d but with 4 4d boards instead
...and then a grid of the 4 4d boards :) Ok, that would be probably too complex.
Let me know if you're going to expand on this, or make a similar game.
