I love the small details in this game. It starts right on the main menu with the box being tossed around in a loop. There are the working sound and music sliders which FEEL good to adjust. The exits matching the robot's shape and him plugging in to charge. The controls being explained on in-game monitors. The writing on the walls. All of this polish makes the game feel great.
As a keyboard user, my one complaint is I would like another button added to select menu items, close to WASD so I don't have to bring my second hand to the keyboard for the sole purpose of hitting enter.
The visuals of the game are beautiful and communicate the elements of the levels well. The robots eyes help him stand out, and I like his shut-down animation.
The music was lovely, and is set to a good volume relative to the sound by default. It sounds like a short, simple loop, but I never noticed it getting old or annoying. The music on the last level was a jam, I wish there were more levels so I could keep listening!
You have the solid foundation of a great game here. Good job! Now just add more levels, and maybe a few more mechanics to give yourself fresh level ideas to work with! I'd love to keep playing :)