I really like the art for this game. That being said, I had no clue what was happening my first three attempts. There was no in-game tutorial and I figured out the controls just from guessing traditional WASD controls. I was very confused that arrows were used to attack, given that the arrow clicked had no directional impact on the attack itself. Maybe left clicking or spacebar would have made more sense for the attack button given normal genre conventions?
I also was thoroughly convinced that the blue attack only shot out 3 orbs for a few runs which made no sense to me. Then I realized that it shot out 4, one in each direction. I then realized that there was no indication if an attack had hurt an enemy. Because the enemy didn't flash, make noise from being damaged, or have any sort of indication that it was damaged, I assumed all of my attacks just weren't doing anything. If enemies don't instantly die, you need to show that they were damaged somehow, otherwise it can confuse players. This applies for the player character too, I could never tell when I actually lost a heart and when I didn't since there was no visual indication.
I actually never really paid that much attention to anything in the UI. I occasionally glanced up to see what attack was next. But eventually, I just started looking towards the bats and attacking since both attacks would hit anyways despite them being different. So then which attack was next become mostly irrelevant since I never made it past wave 3.
The game needs a lot more visual communication so the player understands what's happening as well as a tutorial. For this game, a tutorial could be as simple as, before the game starts, show WASD and the key that fires the attacks on screen. That's all you'd need for this particular game. Overall, I think the game could be really fun with a little more work. But, you made a game in just 48 hours and that's a tremendous accomplishment. You should be very proud :)