Played for 39 minutes - completed 15 levels, I'll return to the 16th later.
Very strong candidate for my video of best jam games. One thing I would add in general though: make everything happen faster: restart, next level, settings, placement - all should happen in about 0.2-0.4 seconds. It's currently very slow.
Extra level notes:
- 10: you only need a zombie and one spike (bomb is not necessary)
- 11: at least one bomb unnecessary
- 13 - seemed impossible for some time - I think you probably need to teach the necessary-to-solve mechanic as some isolated level, although it's also cool to discover it in a full setting