Couple bugs or issues I noticed
1. On web, in the final level, the game's framerate really struggled when its spawning it's enemies
2. The restart button at the end of the game has the default text instead of your cool ninja one.
3. More than once I ended up running into enemies on level 3 that were out of my field of view. (Maybe I just needed to play more cautiously, but it did irk me a bit)
Minor gripes aside. Great job! :)