I obtained this when I ran out of time and then handed in a mission. The mission hand in gave me an extra minute which defeated the grim reaper. I assume you can also do this by saving a worker once out of time as that will also give you another minute.
This can be combined with
and
The Outta Time trophy in Flame Over worth 34 pointsComplete a Level with 0 seconds left on the clock. I made a video getting all 4 trophies. This trophy occurs at 7m 45s (can't get the embedded video to play from that point):