Good, room for improvement
Pretty stable TD, fun and challenging(no to bad for me, i constantly play TDs)
~ only thing is, beating it on hard was pretty easy, with only certain towers to be built at once there was no real strategy besdies building up on the old, and it wasnt to hard to figure out ideal tower placements due to no mazing and creeps that only vary in speed and HP.
Could use a few more tower types... but that could be said for any TD
Other than that , it's a good start and if you make a sequel I'm looking forward to it.