Fun premise!
Really like the effects, both SFX and effects on the attacks from Calli and the grems!
I agree that I think gameplay could use a little more depth, and also this it would help to attack in the direction of the mouse, instead of whatever direction Calli is facing - felt a little clunky at times to have to maneuver all the way around to get a good angle to defend myself against the grems and hit Gigi too
But maybe that was intended, not sure
I think that's about it for me, though. Good work!