Player satisfaction levels

1. Player Trading vs Player Selling (Virtual Economy Gamification Tips)
2. Game Playability vs Game Accessibility (Gamification Achievement Systems Tips)
3. Player Targets vs Player Goals (Gamification Player Progression Tips)
4. Player Objectives vs Game Objectives (Gamification Achievement Systems Tips)
5. Progress Bars vs Completion Bars (Gamification Player Progression Tips)
6. PvP (Player vs Player) vs PvE (Player vs Environment) (Player-Centric Gamification Tips)