Absolutely horrible.

First off, you need more everything. More characters, more towers, more buildings, more defenses...
Secondly, you need to improve the rate of the game. on the second level, you give way too much money, and not enough time to spend it. The 3rd wave of like, 50 people came within the first 15 seconds. Some preperation time is much needed, especially for beginners, so you should add a difficulty system, instead of starting everyone out on the same level.
I suggest you make a second one, with much more variables.

Aw, so cute.

Shoot, his cool and stylish glasses musta fallen off during the extreme speeds of liftoff!

AWESOME GAME. 6th day and I was in orbit.

Generally interesting.

Well thought out, many glitches, but you can't stop all of them.
The most annoying was when the ragdoll would get half its body caught on something, and half the body would keep going, until it acted like a spring, and shot back the way it came. Other than that, very decent, but slightly easy. Took me less than 5-10 minutes to beat, so not time consuming, but not addicting either. No suggestions.