Music is great, tell your friend that they nailed it. It was very simple but fun. The voice acting helped the game a lot. Im not sure it felt like it was cooperating with the AI or against it but it was encouraging. Easy and normal were very simular. Maybe alternating between adding and subtracting could be interesting. Also having some form of rng with where the screen blocking AI spawn so that they arent in the same place every time. Overall one of the more polished ones Ive played so far.