This game is totally free and I wrote it just for fun as a hobby -- so there are no ads, no in-app purchases, no premium items or anything of the kind.
I should mention this game is hard. I mean, the first few waves are kind of easy, but it gets difficult pretty quickly to keep things interesting. You will need quick reflexes!
The graphics are pretty minimalistic. I enjoy the old retro pixel based games, so I tried to make it in that style, but using rectangles.
Joystick support: this game supports most Android joysticks with two analog sticks.