I admit I only got to 271 honeycombs so far, but if I may, here's a few suggestions: add enemies that have a smaller size change amplitude, but instead move from one point to another (and later on enemies that maybe chase your for some time?) Also, a sort of super-honeycomb, which gives, say, 10 honeycombs at once, but only appears for a short period of time might be nice to make it more dynamic.
I hope that doesn't sound too mean - I know what it's like to receive suggestions when you yourself if you know where to move the game yourself, although I haven't really finished my main project yet, but I've already got a lot of suggestions from friends, and they were wildly different.)