You need to collect all orbs in each level. You dont need to be able to touch the orbs to collect them, you can touch them indirectly in some way.
The time machine will reverse everything every 10 seconds. So everything will go back to the way it was before every 10 seconds.
You cannot move in time that is reversed from your time. Easier to understand, when you have orange color, you can move normally in the orange world. You need blue to do the same thing in inverse time.