Difficulty balancing

1. Single-Player vs Multiplayer (Player-Centric Gamification Tips)
2. Game Physics vs Game Mechanics (Player-Centric Gamification Tips)
3. Experience Points (XP) vs Skill Points (SP) (Gamification Player Progression Tips)
4. Player Rankings vs Game Rankings (Gamification Player Progression Tips)
5. Skill Levels vs Player Levels (Gamification Player Progression Tips)
6. Open World vs Closed World (Player-Centric Gamification Tips)
7. Player Data vs Game Data (Gamification Achievement Systems Tips)
8. Game Design vs Game Development (Player-Centric Gamification Tips)
9. Player Challenges vs Player Objectives (Gamification Player Progression Tips)
10. Game Testing vs Play Testing (Player-Centric Gamification Tips)
11. Player Goals vs Player Missions (Gamification Player Progression Tips)
12. Player Improvement vs Player Progress (Gamification Player Progression Tips)
13. Player Objectives vs Game Objectives (Gamification Achievement Systems Tips)
14. Player Performance vs Player Scores (Gamification Player Progression Tips)
15. Game Respawn vs Game Revive (Player-Centric Gamification Tips)
16. Level Design vs Game Balance (Player-Centric Gamification Tips)
17. Cognitive Absorption Vs. Flow in Gamification (Contrasted)