Fionna and Cake is Adventure Time’s most impressive transformation yet

polygon.com:

Watching Fionna and Cake is kind of like watching a surprisingly game 80-year-old ball with her grandkids. They’re comparatively limber, but she’s holding her own — and you realize most of what they know they must have learned from her, and while little Billy and Jessica were playing, she was up in the stands learning from them, too.

In the 13 years since Adventure Time’s first episode, the world of fantastical adventure-comedy cartoons for kids has radically changed — and Adventure Time created room for many of the biggest changemakers in that niche, one way or another. What Fionna and Cake proves is that the venerable series can still go toe-to-toe with its competition, playing with its old themes in the expanded ways its younger counterparts created when they borrowed them. What’s more, and perhaps most impressively, it can do it while reinventing itself for its adult fans. Not just by leveling up, but by growing up, and without losing any of its charm in the process.

But then Adventure Time has always been about squaring the circle between endless repetition of the form and endless reinvention of the work. The series is a 283-episode colossus standing astride the gap between the short, episodic action-comedy fare that defined the biggest successes of American Saturday-morning cartoons in the ’80s and ’90s, and the long-form, world-building, wiki-spawning epics that define that niche now.

Adventure Time began with Pendleton Ward’s student work about a princess-rescuing boy adventurer with a sword, a talking dog, and an ice-slinging nemesis. But thanks to Ward’s creative generosity, it gradually morphed into television’s equivalent of an exquisite corpse — and a truly exquisite one at that. By season 3, the show