Really like the concept! I would've rated "fun" 4 or 5 if it were expanded on a bit more, because in the current level, all I needed to do was stand still and shoot back and forth until all the enemies were dead, then get one player stuck in a corner and run to them with the other player.
However, it's super impressive to make something that looks so good in 48 hours, and I imagine that took up the bulk of your time, so either way, I'm very impressed!