Time Saver Achievement
Save 300 seconds worth of time.
To unlock this achievement you will need to collect 100 of the little clock items that you start seeing in level 15. The achievement is cumulative, though, and you will likely pick up way more than 100 over the course of the game, since there are dozens on both of the last two levels and a few on the fourth bonus level on the path to the nine hit protection item. Level 15 is quick and has a few easy to find ones, if you just want to get this out of the way.