Two hours of awesome is always better than eight hours of decent, IMO. On the other hand, it can be a bit disappointing when a great fetish game abruptly ends while I’m enjoying myself. My personal ideal would be a game that’s both long and consistently great throughout.
However, even the best gameplay experience can overstay its welcome. In order for a game to be both long and good, it needs to include enough variety or escalation to keep things interesting. Pieces of content can be excellent on their own, but they can feel like filler if they’re too similar to what the player has already experienced.