Time Experiment Hacked

You were abducted by aliens, and now you are participating in the experiment with the time.
You have a time-machine clock with three buttons:

Play - normal movement of time.
Stop - Stop the time relative themselves.
Back - wrap back movement of time, carrying himself to the past ( you can change the past, but without changing yourself. )

With this clock you have to get out of the levels - puzzles.