Connie murdering every boss in Save the Light 

Steven Universe: Save the Light sure has balance issues
Anyway I'm not really a Steven Universe fan, but Save the Light is a short but interesting little RPG. While I wouldn't call it a favorite of mine (it's very, very janky in places), it has an interesting style of ATB combat. Rather than each character getting individual turns, your whole team gets Star points for you to use, and you can use it in pretty much any way you want. You can act immediately after getting points, you can also play defense, hoard points and then let your characters attack five times in a row.
The system isn't without its issues. When you run out of Star points, there's a lot of dead time during battle just waiting to get more. Most skills aren't balanced well (some skills are too strong or too weak for their Star point cost), characters are poorly balanced (Connie is far and away your best attacker because of her stackable Reading buff), the game doesn't give you enough info (choosing not to explain certain mechanics at all, and it doesn't show you the duration of certain skills) and you only get 10 Star points max (12 if you get a lategame Badge) which isn't much to play around with.
It's a shame that its sequel, Unleash the Light, dropped the ATB combat system, instead going back to the mobile RPG gameplay of the first Steven Universe licensed game (Attack the Light). Someone really needs to steal this game's ATB combat system and do it better, because there's a lot of interesting ideas here.