Time-based challenges

1. Gameplay Evolution vs Player Evolution (Gamification Player Progression Tips)
2. Achievements vs Trophies (Player-Centric Gamification Tips)
3. Game Sound vs Game Music (Player-Centric Gamification Tips)
4. Active Achievements vs Passive Achievements (Gamification Achievement Systems Tips)
5. Game Objectives vs Player Objectives (Gamification Player Progression Tips)
6. Player Targets vs Player Goals (Gamification Player Progression Tips)
7. Player Improvement vs Player Enhancement (Gamification Player Progression Tips)
8. Experience Gain vs Skill Gain (Gamification Player Progression Tips)
9. Game Sequel vs Game Expansion (Player-Centric Gamification Tips)
10. Replay Value vs End Game Content (Player-Centric Gamification Tips)
11. Game Progression vs Game Advancement (Gamification Achievement Systems Tips)
12. Gameplay vs Game Plot (Player-Centric Gamification Tips)
13. Gameplay Strategies vs Player Strategies (Gamification Player Progression Tips)
14. Game Scenario vs Player Scenario (Gamification Player Progression Tips)
15. Game Unlockables vs Game Achievements (Gamification Achievement Systems Tips)
16. Player Challenges vs Player Objectives (Gamification Player Progression Tips)
17. Player Control vs Player Autonomy (Gamification Player Progression Tips)
18. Player Skills vs Player Cap (Gamification Achievement Systems Tips)
19. Prior Knowledge vs Background Knowledge (Gamification-Based Learning Tips)
20. Learner Engagement vs Learner Motivation (Gamification-Based Learning Tips)
21. Game Storyline vs Game Scenario (Gamification Achievement Systems Tips)