This game is super fun. The graphics, music, sfx and font all work together well. The level designs are also very good. The random levels option at the end is also appreciated. 😁
Just for feedback: I tried using a gamepad as well, but the zombies can't jump. There were some instances when they won't move so I would go back to the keyboard. Then after a bit, they would respond well to either keyboard or gamepad. But I still couldn't get them to jump with the gamepad. Maybe this is related to the known issue you mentioned about the jump button not responding? Hope this helps!
Excellent work!