Finally! The answer to the eternal question: "what if evolution was replaced with a suture kit and a 'finders keepers' policy?".
What really makes this one is the fact that each upgrade makes certain coins in each level unattainable; you have to plan your route so that you don't lock yourself in an unwinnable state.
Like Mr. Wormy himself after an encounter with a lawnmower, though, it is all too short: there is fertile ground here for more levels. I'd love to see you expand on the concept.