Good job with this game! It's straightforward and easy to grasp, but is challenging as well! I like the music as well!
Couple things. The timer, at least for me, was counting down quite fast. I see the game was made in GameMaker. Were you counting down using a timer -= 1 type of deal in the step function? If so, you may want to check the preferences of your game to see if it's running at 30 or 60 fps - it felt like it was counting down 1 second every 30 frames while running at 60 fps. I know that it's supposed to be magnets controlling the main object, so it's not supposed to feel snappy and responsive, but it felt almost too slow to change directions as quickly as was needed in certain circumstances. The punishments for hitting things felt almost too severe as well - A box would make you lose 6 or 7 seconds (based on the in game timer) which is a long time to be hanging in the air before you start falling again, A trampoline would double that time, and a saw makes you start the game over from the main menu... I think an option for either going to the menu again or restarting at the start of the first level would go a long way.
The art of the game was just a little jarring to look at, to be honest. Sometimes, that sort of patched-together feeling works really well, but in this case, it just didn't look super coherent to be honest. Super detailed clouds in the background, with pixel art boxes and a ball bearing(not sure) that looks like a JPG just didn't look like one cohesive vision, you know?
Overall, I think you did a good job with this game in a lot of ways, but it also has some room for improvement!