"What counts as fan service?" asks William Hughes. "Is it just the surface-level, feel-good stuff that gets the long-time viewer’s adrenaline pumping—the big action set pieces, the cool new songs, the ’shipper fuel and the exciting cameos? Or is it the deeper satisfactions, too: the elements of a long-running series that finally explain key moments or mysteries, or that pay a toll of service to fan and character alike? The term carries with it a heavy host of indulgent, negative baggage. But at its best, 'fan service' can be as simple as offering viewers the things worth delivering, something like a happy ending earned, not given. In that sense, HBO Max’s latest Adventure Time: Distant Lands special, Obsidian, qualifies as fan service at its finest. After all, what is the whole Distant Lands project—which began on the streaming service with BMO back in June, and which will continue with two more 45-minute specials after this one—if not an extended exercise in victory lapping, allowing Adventure Time to check in on its dazzling array of beloved characters, see how they’re doing, and then (possibly) bid them a fond and final farewell? (You’ll be missed, Choose Goose.)" ALSO: Obsidian isn’t as offbeat as BMO, but it’s heavier in plot and emotional weight.