I'm having a heck of time with levels 2 and 3 as well. My aging brain just doesn't have the coordination that it used to LOL.
So far the part that I have the most trouble with is in level 2. I can get up the first conveyer belt fairly easy, but the boss at the lower right gets me every time. Also when delivering the toolboxes to the magnet, I have a heck of a time getting the magnet to grab the toolboxes without going up the conveyer belt and dieing from the fire at the top right. In-game demos of how to beat the levels at the title screen would be great! :)