Excellent
This is some great stuff! I love it! The combinations are going to take a while to memorize (if I ever do memorize them) but they are a great addition.
At first, I was disappointed because the game said I won...I thought to myself, that's what I hate about the really good TD games--they always end right when they're getting good. But then it went back to the map and I realized that was just one level =p Kind of long for a single level, but I'd certainly rather too long than too short. And yeah, something above 3x speed would be nice.
+favorite, +5/5, +10/10. Good work.