Great use of theme, both with waves of enemies and EM waves. The visuals are quite nice, although some additional SFX would have been nice. The main mechanic of damaging enemies with different frequencies was neat, and I like that being off by a little doesn't entirely mitigate the damage, just reduces it. Also, it was quite interesting playing a wave-based game where you roam to the next site to defend; I'm used to it either being the player's life that's being defended or having a fixed position you must defend throughout the game. This added variety in a cool way.
Nice submission.