At first I was a little bit confused how the towers worked, but after fiddling around the game is quite engaging. Could be a little faster in my opinion, or maybe have a 'spawn next wave' button. Good job!
Both of the features you have requested are available in the game, though not explained in the in-game tutorial. You can speed up/down the game with the ] and [ keys and you can skip to the next wave with the Backspace key.
