I've never been a huge Adventure Time fan, but I did love some of the episodes here and there (oddly enough, most, if not all, of my favorites were boarded by Ms. Sugar). The main problem I always had with Adventure Time was the lack of unfinished story arcs and background characters, which Steven Universe, on the other hand, excels at. I was never satisfied with how the Lich was, both as a character and how he got "defeated". Honestly, did he just turn into a giant baby? I always have the feeling that the Adventure Time crew needed a way to get rid of him, so they just turned him into a baby (it's probably more than that, but for as a set-up Villian as he was supposed to be, why couldn't they come up with a better way for his defeat to happen?). As of side characters, they mainly show up for one or two episodes, and then it's like you never see them again. Probably as a cameo or a five second dialouge appearance, but that's pretty much it. Steven Universe is able to complete its story arcs while leaving some for future mystery. For example, the Diamonds. The Diamonds have been here since episode eight, Serious Steven, with the mural in the background of the mystery dungeon temple. It's leads up to speculation, lore-post, and all that good shtick. Then for almost a handful of episodes, the Diamonds are brought back up in The Return. It's an arc that wasn't just left off for nothing. Final statement is that Steven Universe has a good amount of background characters for the show to flow in a smooth pace. Beach City is literally consisted of about fifteen to thirty people, which is a great amount for characters to have their time in the spotlight. While we haven't seen some for a very long time, I'm positive that they're going to have their fair share of screen time. A character in Steven Universe has enough personally and background as the next. Take Ronaldo for example. Sure, he isn't the fan favorite (personally, I like Lars as a better character, but that's besides the point), but he has gotten episodes where we got more information on him. Episodes like Horror Club and Keep Beach City Weird tell us how weird this character is, which is pretty great.

Now, Adventure Time has its moments where it was outstanding, but with the season and half Steven Universe had compared to the seven Adventure Time has, it seems like Steven Universe is able to do so much in a fraction of that time.