That was really good! I enjoyed my time with that a whole lot. I got to the end too, and felt it had about the right number of levels, and they were about the right difficulty. Even the onboarding puzzles were well paced - very hard to do in a games jam setting where you don't get to see much feedback from playtests etc.
Before it introduced the B key to return to the bot, I struggled to move the box in level 2. I was starting to think it would continue to be a frustrating experience, but on the very next level it showed me that was a deliberate trap, and how to solve it. I'm guessing if I went back to that level B would have still worked, and made it a whole lot less trouble. That was a wonderful lesson!
I think I solved a lot of them in unintended ways, but I liked having the freedom to solve things the way that worked in my head. Stacks of buttons holding each other down were a particular favourite technique for me. Sometimes there were boxes that I never touched at the end of levels, but that's a joy in a world where most puzzle designers would block off unintended solutions.
I thought the music was OK, but a little bit short to loop continuously like it does. Not a lot of variation too, so it kinda grates a little bit. I'd have appreciated an option to turn it off, but I totally understand games jams force you to prioritise things that really matter, and appreciate just how many other features were competing for your limited resources.
The controls weren't exactly to my taste. I found it hard using A/D to move, but not W to jump. Then there's E to swap (that's fine) and B to return? That's a bit of a stretch, and occasionally I found myself automatically pressing R and resetting the level, when I meant to press E or Space or B. I wonder if keeping to one button to swap souls would have helped - you could maybe hold it for a half second or so to return to the robot.
Anyway, great concept, great fit to the theme (I was genuinely surprised when I discovered I could move buttons and lifters), great presentation. Great!