Another interesting entry in the Kevin series.
The graphics were nice and jank, the sounds were suitable, and the platforming while not terrible did make it near impossible to avoid damage and losing all my gears at some points. It grinded my gears. It especially didn't feel great with the flying enemies as they felt pretty unforgiving with how far above them your character sprite had to be to count as an attack.
As for the dating sims boss fights, I found it really hard at first until I discovered there was some rhythm to it. But then when I got to the rhythm based section I found it very unclear how well I was actually doing. I ended up having to lean on the IDK button just to progress. I admit I haven't played Undertale so I don't know how much of this was supposed to be intuitive or not.
Ultimately I think this was well made, and clearly it was created with love and effort, though I also don't think I'm the target audience of this kind of game. But that being said you did great work!