Decent, but tedious.
The game wasn't bad for a lemmings-esque game. Most of the levels are really easy, but because of game mechanics take several attempts to finish. So if you walk in looking for a puzzle game (what I assume it's intended to be) you find a lot of speed clicking (my main beef because I don't have a mouse right now).
Either way, 7/10 for good idea, decent implementation. Make the puzzles a little puzzly-er and fix up mechanics for a 10. (Still good for a flash though).