Hi, first of all I liked the addition of start and end point indicators. They made the game much more understandable. Other than that I couldn't see what else you added as I wasn't able to progress much when I tried the game during the submission phase.
Other than that, a quick rundown of the traps in a certain level while you show the levels name might be good as there are many nice traps and I udnerstood some of them "after" they sprang and killed a few mushies :)
I liked the levels and changing themes and traps per level, and encountered no bugs even when I tried with no valid paths.
Also was there an end point or was it an endless runner? Maybe addition of a number of mushies needed to win the game could be a good incentive to contiue when you run through all levels and start repeating?