Mini-game is only fun if it isn't tied to progression. In TES Oblivion, FO 3 or Risen, the lock-picking or computer hacking mini-games are only fun for the first few times. After that they become a chore. I don't think I have ever read anyone going "Oh wow I lock-picked that difficulty 100 lock, it feels much better than blowing up that Super Mutie with Mini-Nuke".