Cool game! I like the visuals and special effects, everything's presented really nicely.
Knowing where you need to move to trap the beasties takes a bit of getting used to. I found the enemies that came and destroyed the points I'd laid down really hard to beat which put me off by about level 3. I think it could make a pretty fun game and is just the sort thing I could imagine on XBLA but the gameplay and difficulty curve needs a bit more work.
Cheers,
Dave
http://www.smudgedcat.com