Thanks for your comment and all of your kind words. Yes, the robot is the main character. Before starting the development we even had the idea to add an option to play as the robot instead of the broken parts and fight the broken parts.
While the game is actually difficult it should've been giving you extra lives as you play. There's a bug that makes the game harder after you die once, bullets overlap and you don't get any extra lives. If you restart the game every time you lose you can get rid of this bug.