Oh wow! I just assume any game that looks nice (and isn't using art assets) had at least 2 people working on it XD The 48 hour deadline is rough x.x I wasn't able to playtest my game much either so it has similar problems.
All in all, you did great in the game jam ^^ Oh! One sidenote I forgot about. If you hold crouch and jump once your horse starts to fly.
Whoever submitted the game can include you as an "author", like I am in this game: https://petersome.itch.io/santas-jam . Altough I'm not sure if Itch will show the game's thumbnail below your profile pic.