Visuals and musics is really good! The menus are also among the best that I've seen in a Jam :)
Congratulations!
Some feedbacks regarding the game mechanic:
- I feel like the bosses had too much HP and this made the last ones overstay their welcome .
- The game needs some risk/reward system, since in the current state strategy is not necessary to win.
- Maybe allow multiple ninjas attack the boss at the same time? Or select which one to spawn and gave each one a different strategy.