Fun and really well made! I like the variety in bugs that can be used.
With regards to the scoring system could it be changed so that rather than being a combination of time taken and money left at the end, it also counted the sum cost of the units still alive? I ask because in my first run I got a score of around 1475, but in my second I only got 615 despite being much faster (and I had a lot of units still alive at the end)
Other than that this is a really well made reverse tower defence game, would love to see more levels added!