Nice game!
I liked the 7th puzzle (it was definitely the most difficult, but perhaps doesn't belong with the first 6).
I liked the feeling of the magnet being pulled when held by the robot. Maybe it would be interesting to play with the idea of switching between polarities while holding the magnet for platforming (I know players criticised platforming sections in the previous demo, though).
I wasn't a huge fan of the default controls. I only realized afterwards that the right-click could be used for throwing, which I think I preferred, although maybe there could be a way to throw the magnet without having to use the mouse, which would also feel more natural.
Throwing the magnet felt a little clunky since it felt like a pause from gameplay. Maybe allowing the player to move, or throw the magnet accurately without using the mouse would be good (using WASD instead, perhaps? "W" would be nice to easily throw straight up).
Having to reset some levels repeatedly was a little annoying. I didn't realize until afterwards that the control button had to be held to reset, perhaps the symbol shading in slowly or having a loading bar could make this clear.