The sound design and music is great, and I really liked the short storytelling at the beginning and the way it presented the controls of the game! The big zombie ray felt great, especially when killing a lot of humans at once. I didn't feel much the presence of the zombies sadly.
Also I found myself a bit further from the center of the map and all the humans arrived two by two from the left so it wasn't very difficult. But at the beginning when there were loads of them at once and I had to dodge them a bit bullet hell like it was great! Overall very nice game, well done :D