From all the games I've tried, your to first one with a reversed tower defense! I really like the way you execute it.
I wasn't expecting to see a game with gamepad controls in the gamejam.
For keyboard and mouse, it was difficult to press both WASD and 1/2/3/4 at the same time. Since pressing WASD require the usage of all three middle fingers, I recommand using key that are closer to the thumb and little finger (e.g. CTRL, Shift or space bar!) Button on your mouse are also free. :)