Played this for way too long haha. It is enjoyable and I like the various types of things you can place. Also the enemies look cute as heck, how they wobble around : )
The only complaints I have are, that first, the big armored skeletons seem to have *way* too much health late game.I had like 7 towers, some lightning towers, flowers for slow down and not a *single* one of the big skeletons died.
Secondly, I am like 99% sure that the game does not behave the same way when sped up. Sped up I always die in the first wave most of the time. Slowed down I make it to wave 8 at least usually : P