Trying one of the recent games at Kongregate, I discovered a game (and accompanying achievement) for pure grinding, Mighty Knight. It has the usual more-or-less required upgrades, but some “quests” remove the “more-or-less” by removing all player input. Those quests are to have your NPC companions defeat all the enemies. You cannot command, control, or guide them in any way except for buying them better equipment. Your NPC companions also select targets at random and fight them to the death, no matter what else is going on around them.
As I type this, the game is rated 3.9/5. Either most folks operate on the 7-10 rating scale or the average gamer just utterly baffles me.