Love It!
Got as far as level 19 (X8SOV) and this is great! Outstanding 3D graphics fused with an devilish system of puzzles = Win! The only suggestions I could come up with were these:
1) Put in a level editor.
2) In the minimap in the corner, if the stacks of cubes are higher, put numbers on top of the squares, so the player can play only looking at the small map.
In fact, if you could do number 2, you could make it a PSP game!