• 56,418 Achievements Earned
  • 3,697 Players Tracked
  • 50 Total Achievements
  • 8,470 Obtainable EXP
  • 1,000 Gamerscore
  • 192 100% Club

Got a medal on a challenge in Sandbox Mode. It says "Participant" in small letters at the bottom…

20
56.40% Uncommon - 59.00 EXP

You have not earned this achievement yet