While it took over 3 hours, this is fantastic! Really really well done, smart, fun, good ideas. Nothing revolutionary but the world could always use more magnet physics games.
A fair bit buggy as all physics games tend to be, moving on cubes is always tough, jumping was shortened randomly sometimes, stuff would just kinda glitch and slide off occasionally, buttons wouldn't activate right away and have a weird inconsistent delay, but the main thing was the right-click to turn a red object into a magnet. I think this is the game's best mechanic, but it was so buggy I almost stopped playing right when it was introduced. It was just refusing the work, took way too many attempts doing the same, very obvious thing (right-clicking the red button to attract the box and open the door). There are a lot of UI/UX changes that could really improve that, like changing the cursor/changing the color of the object slightly when you mouse hover-over a red object that can be made into a magnet, and especially changing the color/image when you turn a red object into a magnet, as that's a toggle effect, yes? And of course sounds to reinforce the controls every step of the way would add a lot for very little.
Still, this was very well done, really great. The level design and tutorial design is very well done. Overall, just great. Keep it up.