The game's movement feels really nice! I've been in jams where we took days just to get smooth platformer movement down, and you nailed it. I also love how consistent and stylistic the visuals are. The color palette is very pleasing on the eyes. And the animations, while minimal, have a lot of life to them - which is impressive for such a small pixel resolution. Cover art is also lovely. Moreover, SFX are really nice and crunchy without being grating, though I do wish the game had some very subtle SFX footsteps, just to fill the empty air.
I think the decision to go with randomly-chosen but handcrafted rooms was a really good one, because they're all very distinct and nicely designed. On the other hand, the game doesn't really get more challenging once you get used to it, since most rooms are about equally difficult. It may have been a good choice to have a pool of Easy, Medium, and Hard rooms to choose from. Then the game could choose to start with the easies, then the mediums, then the hards. I think that would allow for a difficulty curve while still having random rooms. I also got two of the same room in a row at some point, so eliminating levels from the pool once they're generated would also help create a sense of forward momentum.
Overall, I'm happy I stumbled on this little gem. I could easily see this turned into something more developed.
Did you make this on your own by any chance? I'm impressed.