This game is amazing I don't know what these other fools are talking about; they obviously don't know their ass from a hole in the ground.
Frostwerks: the buttons work ALL the time. They are physics based...
Christw5: the controls work 100%.
Make sure all your objects are being properly cleaned up. I had a glitch where I resumed from a pause to die and then some objects were stuck on screen, washed out.
 "Spewer"){kind=icon}
 "Desktop TD Pro"){kind=icon}
 "Momentum Missile Mayhem 2"){kind=icon}
 "Cell Warfare"){kind=icon}