busted game—jumping doesn't work most of the time, projectiles come out of the wrong places, some enemies are stuck, default unity assets

Third thing I did, jump left over the starting building and fell off the map

Did you use Red from SuperGiant Games "Transistor"? I'm pretty sure that's what the thumbnail is (I could be wrong). you should at least credit the artwork if your gonna use their character.

I fell off the map without even trying to.

I think some clarity could really help this game out.
For starters, explaining what the controls are for the game. Even if it's just in the description. For a couple minutes, I didn't realize I had a jump button because there's no key binding for the W key.

Right now, this feels more like a prototype rather than a complete experience (which is totally fine). The art assets are nice and there's some cool little details with the audio but the core mechanics aren't really refined and there's a lack of purpose to this game.

Also, take some notes from how Ori and the Blind Forrest designs their levels. I feel like their design principles could align with what you are trying to achieve both from a visual and design perspective.

Hopefully in the next update/release, you address these things!

Until then, best of luck :>