Jonathan Blow, Creator of Braid, Discusses Game Design

[Macatone]

I agree with this statement. However, as Jonathan Blow has pointed out, this system also allows game developers to "exploit" its players, putting them in a never-ending loop of grinding and unlocking. Such a loop can be seen in games such as World of Warcraft. Of course, I really enjoyed that game when I played it, but thinking back on it, the addiction factor that goes hand-in-hand with progression does cause some sort of problem.

I see your point. So the continual "playing and unlocking" is a way for game developers to get you to continue to play their game and possibly getting addicted to it (which could cause a problem).