the progression of the enemies is great until wave 4 when the enemies have the equivalent of a shotgun.
i like it when the robots upgrade, they get a different sprite. balancing issues FEEL like the second robot from the top is extremely powerful and the cost is easily pass via the beacons. i feel as if leveling should increase price by even the slightest and/or preform a more visible function. the fifth robot from the top... i don't know it just doesn't feel as powerful. the shield isn't exactly obvious for me
the sprites are great and it could benefit from some bgm