Leaderboards and achievements

1. Gameplay vs Game Plot (Player-Centric Gamification Tips)
2. Immersion vs Presence (Player-Centric Gamification Tips)
3. Game Progression vs Game Advancement (Gamification Player Progression Tips)
4. Difficulty Curve vs Learning Curve (Player-Centric Gamification Tips)
5. Gameplay Evolution vs Player Evolution (Gamification Player Progression Tips)
6. Personal Progress vs Comparative Progress (Gamification Player Progression Tips)
7. Player Data vs Game Data (Gamification Achievement Systems Tips)
8. Tradable Items vs Non-Tradable Items (Virtual Economy Gamification Tips)
9. Trade-off vs Opportunity Cost (Virtual Economy Gamification Tips)
10. Virtual Profit vs Digital Profit (Virtual Economy Gamification Tips)
11. Voluntary Exchange vs Forced Exchange (Virtual Economy Gamification Tips)