Best game I've played so far! I went in blind so I beat the entire thing without realizing there was a speed boost key, and I used up my first lovebomb by accident while trying to pause the game, but the gameplay and graphics and music all felt so smooth and professional I could have easily seen this as a full game for sale in stores! And it fit the gameboy aesthetic perfectly, I can imagine playing it on a real gameboy - the only difference I can think of is that this game lags way less than a gameboy would, haha.
The only possible critique I could have is that a pause menu would have been nice, even if it just brought up a black screen that said "PAUSED". Was watching a stream while playing, so I would have liked to pause so I could reply to something every now and then, but had to settle for between stages and during any brief mid-stage pauses. (Edit: Oh wait there is a pause button, it's just on ESC which is so out of the way I didn't think to press it. Maybe Enter would have been a better choice?)
PS: Fun fact, when first trying to find which button started the game, I somehow hit a weird key combination that shut down my entire browser. Oops. Also, I was weirdly happy to see another game that both used the default palette and had a screen resizing option! I'm not alone in that!