This game can be played fairly quickly. We played 5 games and each lasted about 15-20 minutes.
At first my fiance didn't like the game, but once he got the hang of it, he liked how easy he could win. I played this game with my cousin before and I enjoy this game whether I win or lose.
This game could be educational and very useful in a language course. I picture using this course right after teaching numbers and counting. I would add a rule that you have to count out loud and if you cannot remember the next number while you are counting, you have to give your remaining rocks to your opponent.