A nice twist on an old genre.
I started playing this game and my first thought was, "well its just another tunnel game, nothing special here." Right after that the direction of the tunnel started spinning around in circles. Definetly a fun and original touch that kept me on the toes.
Also a good job an keeping the file size to a minimum, you lost a little bit in terms of graphics and special effects, but who needs 'em. When you've got a game thats this simple, fun, and engaging it doesn't matter.