Sometimes I have to reset because the gears/platforms are at the wrong position at the wrong time.
For example, there could be 2 seconds left on the countdown, but the platform in front of me is deactivated, so I need to waste those seconds waiting for the platform to activate again, and the countdown runs out through no fault of my own. Basically, everything is unsynchronized and that's a little frustrating.
Also, gears are least platformable shape.
To be fair though, most of this stuff doesn't really matter until the last level. The game is quite enjoyable up until that point.