Wow, good job dude! At first I had a hard time because I thought I couldn't kill the enemies, I would suggest making an animation for the enemys showing that they got hit, because I thought my projectils were just supposed to push them away. But once I find the second character I was like "Oh hell yeah here we go, now let's see who kills who!". I also found amazing that the timing of the bullets made them sound like a heartbeat.
I found a little issue with the audio in case you wanna fix it, if you change the volume settings and go back to the main menu they reset to their original values.
Keep up the good work! :)