Wow! This is an incredibly polished game with very clever level design and brilliantly executed mechanics! The music and art work really well and the option to toggle music is a really nice feature. I did not fully grasp the magnet strength idea and also couldn't get past the 4th stage (not your fault, I just didn't have the patience), the parts I did play were really fun and polished. Well Done!
(Also, are you pushing around Magneto's helmet?)