Cosmo Run

While going for the "The Devil Within" achievement you will be practicing/grinding a lot, and unavoidably getting better and better at the game. At first it will seem tough and stressful to score over 200, but as you play more and more, scoring over 200 will be very easy. To put it in perspective, while grinding to 200,000 I consistently score over 1000 on my runs, and I was really bad when I first started playing too. You will get better, it just takes practice, and then this achievement will come naturally.

You of course also have the option of using Save Me to keep your run going. Stars will be scarce initially though, so you'll want to try not to waste them much. For this achievement, as you get better and work on getting to a score of 666, wait until you have two runs in a row over 200. Then, if you screw up on the third run, use Save Me to get you that last distance you need to get to 200 on your third run. Just remember that you will get better as you play more and you'll be meeting these requirements on a regular basis.