When Adventure Time first started, its imaginative world was used to create surreal and unique stories for laughs. For that reason, the 8-minute time slot was perfect. You understood that there were hidden messages within the show which made you wonder what was beyond the humor. However, the jokes were what kept you coming back for more.
Adventure Time has changed over time for the better-- Mostly. Let me explain. The world is much more fleshed out. The characters have added depth, and in my option, the adventures are more clever and epic. However, the episodes now have more plot to show and in the same amount of time as before. In my opinion, this causes the pace of the show to feel rushed. For example, in this episode, Finn is faced with a great and terrible creature. I won't spoil who it is, but I was hoping that episodes from the reveal to the fight was more padded out so you can really understand the conflict.
The main reason for this is due to the format of the show itself. If it was let's say 22-minutes like most shows, then I know that the show would be able to create the emotions that it is trying to convey. I'm still giving this episode 9 stars because it is still everything that you could want in as a continuation of an 8-minute episode. It's just the payoff doesn't feel as impactful as I would want it to be.