The music invokes a very inquisitive and eerie kind of feeling. The spritework is very charming, but I would recommend using a background with a similar pallette ("sterile-feeling") to the characters and boxes, or at least for the first level. The orange reminds me of rusted iron, as if the world was abandoned, and left this bot alone.
The physics for the magnets does feel marginally clumsy, I'm not sure what purpose needing to hold, and then "ready" the box with a second button was. It didn't impact on the overall experience, however.
It was rather short, and it didn't feel like the main mechanic was given justice.
Good luck on expanding it out, there's a very decent framework here.