Thank you, I finally have some time to get around to replying to most of these comments so I'll try to address most of your criticisms. I am probably going to add some visual adjustments to each enemy in the first level depending on the environment. I'm also gonna add some small season-unique details, like pumpkins appearing in the Autumn alt of the first level, snowmen appearing in the Winter alt, etc.
As for the contrast between the UI elements and the actual game, I wanted to keep the UI a higher resolution mostly for legibility's sake, but I'll try to think of something to make the appearance of the UI elements mesh better with the gameplay.
I'm considering changing the default controls to something like left/right/space/Z or something like that because it seems like a lot less people are familiar with using Z and X as default controls than I thought. I'll definitely add in a proper tutorial for the full release, though.
The camera is an issue I'm not too certain about how to fix yet. I think being able to move upwards would definitely add a lot to the game, but at the same time I wanted to allow downward movement exclusively in order to make the player consider whether to continue moving onwards or stick around in the current area to pick up any remaining collectibles, but ultimately I think the freedom of moving upwards is more important than that. I'll probably allow moving back upwards in the full release, but I want to add some force to the game to encourage the player to keep moving down and not stick around in their current location for too long. Maybe a timer or something, I dunno. I'll have to think about it more.
Finally, changing the key rebinding method should be pretty easy and it's something I'll make sure to fix. Thanks for all of your critiques, I agree with pretty much all of them looking back on this demo and I'll start working on fixing them for the final release ASAP.