Time-limited challenges

1. Achievements vs Trophies (Gamification Achievement Systems Tips)
2. Game Adventure vs Game Quest (Gamification Achievement Systems Tips)
3. Game Difficulty vs Challenge Difficulty (Gamification Achievement Systems Tips)
4. Game Balance vs Fair Play (Gamification Achievement Systems Tips)
5. Game Completion vs Player Completion (Gamification Player Progression Tips)
6. Game Difficulty vs Challenge Difficulty (Gamification Player Progression Tips)
7. Game Tasks vs Player Tasks (Gamification Player Progression Tips)
8. Player Actions vs Player Behavior (Gamification Player Progression Tips)
9. Player Ranking vs Player Rating (Gamification Achievement Systems Tips)
10. Direct Competition vs Indirect Competition (Player-Centric Gamification Tips)
11. Game Advancement vs Player Advancement (Gamification Player Progression Tips)