Disgaea is a game that glorifies grinding and makes it a science. It is an RPG where the level cap is more theoretical than practical, and by endgame you’ve got millions of HP and do attacks dealing tens of millions. I used to grind out a 255-level dungeon during a 40-minute morning workout, it averaged 38 minutes.
The best dang feature of Disgaea DS is it had a clock in the top UI. It was really, really, really easy to sit down intending to spend 15 minutes and find out you spent 45. The clock helped you deal with that.
I wish more games would let my iPhone/iPad status bar display so I could see the clock, or at least incorporate a clock into their UI. I understand you want me addicted, but if I find myself losing track of time with a game I have to quit it. This is why I don’t play Clicker Heroes and a host of other games anymore: I spent one too many 30 minutes when I meant to spend 10.