Interesting use of the theme and the concept felt quite innovative! Nicely done.
I like how the yellow enemies disrupt your frequency adding a bit of depth to the experience. Going from killing samurai to splitting boulders was also a nice change of pace, lol.
Personally I think giving the players more agency on the "tuning" would've been a nice addition. Waiting for the perfect frequency was an interesting take on the samurai standoff but after a while I just wanted more control over the fight. Something like positioning or proximity changing the frequency(?) I dunno.
Anyway, nice take on the theme!