Took about 20 minutes to complete, and here's my biggest takeaway:
Building the proper tools to help you design your game really let you focus on building fun, compelling levels such that I reached the end and wanted more.
A couple minor curiosities (played with mouse and keyboard) followed by personal thoughts:
1) When starting the game, the HUD shows Q to Jump before replacing it with Space.
2) A matter of personal preference, I find the mouse unnecessary if the aim mode could be mapped to the arrow keys, especially since targets are quite large.
3) Instead of throwing your magnet away into pipes to open a door, I might suggest recycling an earlier idea you had; a magnetic block that completes a circuit when the magnet is attached.
4) Ending the level by grabbing a key feels a bit abrupt. But given the quick tutorial level sets up an expectation to use keys to clear the stage, I suspect these levels were more focused on puzzle iteration rather than stage flow.
5) Super excited to see where this project goes from here. Remember to take care of yourself along the way!