Only gave it a few minutes, ran into a bug. I minimized the buildings window, and later called it back up. Problem is, the window was following the mouse at the point where the minimize button is. I couldn't place it anywhere, it would just minimize.
Other than that issue, it looks pretty basic. The grid system is nice, it gives a clear path to plan out walls, towers, etc. The graphics are blah. Honestly, it brings nothing new or innovative to a tower defense game. I'd probably give it a solid 3.
FrozenFire
TD's are pretty popular but good graphics are usually needed now since better TDs can be found anywhere.
I would say you might get a score of around 3.5 but that's about it.