Nice game! Thanks!

Some proposals to improve usability:

The game should notice a stalemate and tell you that you lost (no matter how you rotate: no more progress is possible).

The game should accept a hit of 'Return' to start the new game (it currently seems to insist of mouse interaction).

The game should have a 'fast' mode with less animation so that I can play faster. A single move takes too long! I am impatient! :-)