Graphics and sound work great. Some animation in the "beam" and maybe some particles/effects when it makes contact would really help make it pop. Your music really compliments your pixels and game style. I would have preferred the gameplay to have been a little faster. Increase the robot's speed and decrease the amount of damage necessary to break though maybe. I think the recharge versus frequency could be balanced a little more. The distance/spacing between them feels more random than scaled with how far you've traveled. Fun little one button mechanic that fits within the resolution limitation well. Good job!