You did something really smart here. As i reached the goal, I said to myself. OK, that was fun, but I'm done. Then I realized how you can unlock different parts for your robot. That was an instant hook for me. I went from about to turn it off to having to play again and again to see what all the parts do.
You also did a great job planning the level, it was the same level each time, but because of the upgrades, the player can use a different strategy each time.
Something that I caught that you might want to look into. the physics body that you used for the robot or the platform allows the robot to stand very far off the edge of the platform. There are also physics bodies on some of the walls that the robot can stand on. I feel these are probably unintentional, but if not, that is cool.
The repeat jump when holding W or up arrow was also unexpected.
Overall, great job - its a great example of good game design.