Simple, engaging game. Feels very retro. Great! 

If I had to suggest one thing to improve, it would be balancing the difficulty level. After realizing that the left and right side of the screen are wrapped together, the first level was trivial to beat. However, I didn't manage to beat the second level with following enemies level even once. Many times the enemies even instantly killed the character after spawn/respawn without any chance of surviving.

It's great, really enjoy the retro art and audio, i just found targeting the enemies a little challenging.