It's still in béta, but we have a concept.
I fully agree with 0mg, it needs more variety. This is just the same creeps, spawning the same way, with the same behaviour. They need a personality like speedy, strong, self-healing, and some of them need wings. Also, the towers should have more. Not only basic and splash and shit, but even with capabilities as: awesome power but not very fast. That didn't come out very strong here.
My last point is that your game should have something unique, something that only you could come up with. There are tons of TD games, what do you want yours to have to be special?
Anyway, keep working on it, it definitely has potential.