Open-world exploration

1. Player Choice vs Player Freedom (Player-Centric Gamification Tips)
2. Game Missions vs Player Tasks (Gamification Player Progression Tips)
3. Player Capabilities vs Player Capacity (Gamification Player Progression Tips)
4. Player Experience vs Player Competence (Gamification Player Progression Tips)
5. Player Preferences vs Player Interests (Gamification Achievement Systems Tips)
6. Sandbox Games vs Linear Games (Player-Centric Gamification Tips)