Easter eggs

1. Game Unlockables vs Game Achievements (Gamification Achievement Systems Tips)
2. Replay Value vs End Game Content (Player-Centric Gamification Tips)
3. Game Unlockables vs Player Unlockables (Gamification Player Progression Tips)
4. Gamification vs Game-Based Learning (Gamification-Based Learning Tips)
5. Player Participation vs Player Contribution (Gamification Achievement Systems Tips)
6. Power-Ups vs Boosters (Player-Centric Gamification Tips)