the brain makes the robot functional then the brain just disappear because... magic

An interesting concept. Are human brains essentially ammunition?

You've got the foundation for a good colour palette going with the orange and blue, but the sprite itself lacks much definition. I'd recommend some anti-aliasing on the pipe after some refining of its shape, and messing around with body shapes for the robot; it has a very simple shape right now that could do with some depth, maybe make it look a bit more mechanical.

There's potential in this, and a few edits could go a long way.