For the UI scaling, one option could be to just scale by integer and then pad with black or other suitable color around the game
But yeah I think you did great especially given the constraints you have!
Viewing post in The Hidden Facility jam comments
That’s what we do with a window right now, we base our resolution on 720p and then scale it 2x if it can fit the monitor (so it’s 2560x1440 on a 4k monitor) or even more, if you have 8k monitor for example. We can pad it with black pixels in fullscreen, though figuring out how to scale UI properly between jams will probably be beneficial.