48 hours really forces you to make choices! "Infinite time" is the worst things a dev (or any creator) can have!
Every game I make outside of Jams I really want to do ALL THE THINGS! Sound, Music, Art, UI, and I always end up with half projects that aren't even playable.In Jams, I use assets like crazy! I learn how to find matching assets, how to tweak the shaders so that they look similar, how people structure the assets, etc!
If you want to take a look (I only did code, everything else is free assets from Unity's store):