You are creating a role-playing game that contains regular game-play features.
Which two features help the player to have a strong sense of achievement? (Choose two.)
A.
Rewards for completing tasks
B.
Detailed textual introduction
C.
Numerous ways to gain experience points
D.
Amusing non-player characters (NPCs)
Explanation:
http://www.gamasutra.com/view/feature/132368/unlocking_achievements_rewarding_.php