Nice presentation, I liked the character designs and the music was a bop. I like the idea of the main mechanic, but perhaps it would've been well paired with a basic melee attack or something, so that the act of changing the level modifier was more of a player's risk/reward decision rather than just something that happens at a regular interval. Also a bit of a bummer that most of the effects didn't work on the boss fight - the instakill would've been handy!
Good work overall though!