Challenge difficulty

1. Skill Advancement vs Level Advancement (Gamification Player Progression Tips)
2. Mastery vs Progression (Gamification Player Progression Tips)
3. Game Difficulty vs Challenge Difficulty (Gamification Achievement Systems Tips)
4. Game Difficulty vs Challenge Difficulty (Gamification Player Progression Tips)
5. Player Motivation vs Player Satisfaction (Player-Centric Gamification Tips)
6. Player Objectives vs Game Objectives (Gamification Achievement Systems Tips)
7. Game Tutorial vs Game Introduction (Gamification Achievement Systems Tips)
8. Game Performance vs Player Performance (Gamification Player Progression Tips)
9. Player Progress vs Game Progress (Gamification Player Progression Tips)
10. Game Rewards vs Real-World Rewards (Gamification Achievement Systems Tips)
11. Player Learning vs Player Progression (Gamification Player Progression Tips)
12. Player Ratings vs Player Rankings (Gamification Player Progression Tips)
13. Game Progression vs Game Advancement (Gamification Achievement Systems Tips)
14. Player Skills vs Player Abilities (Gamification Player Progression Tips)
15. Player Effort vs Player Reward (Gamification Player Progression Tips)
16. Player Improvement vs Player Enhancement (Gamification Player Progression Tips)
17. Player Investment vs Player Commitment (Gamification Achievement Systems Tips)
18. Player Learning vs Player Growing (Gamification Player Progression Tips)
19. Game Completion vs Player Completion (Gamification Player Progression Tips)
20. Player Achievement vs Player Advancement (Gamification Player Progression Tips)
21. Game Playability vs Player Playability (Gamification Player Progression Tips)
22. Game Adventure vs Game Quest (Gamification Achievement Systems Tips)
23. Player Goals vs Game Goals (Gamification Achievement Systems Tips)
24. Achievements vs Trophies (Player-Centric Gamification Tips)