Very cool game!
I'm just gonna highlight some of my thoughts below:
1) I really liked how each type of unit had a unique color for their attack, I felt like that really helped differentiate what was going on especially when the waves got really intense.
2) I know based on the comments that the camera switching has been a little hit or miss with some folks but I actually really liked it! It did take a bit to get used to but I actually enjoyed trying to puzzle out from the top view where I actually was placing units in the 3D world.
3) Really cool music! The sound effects were nice and meaty too!
Excellent job!