I'm the solo dev (graphics, animation, code & music, etc) of 9th Dawn III and I'm at the end of a 3.5year dev cycle of my game. I decided to use Spine to animate all my monsters (and some mapbojects, and GUI!) as I wanted a fully animated world and to try make something look a bit different than other pixel art games. I'm not sure if there are other pixel art games using Spine? Here is an example of the idle/walk animation of some of the monsters:
It was very challenging, but I found Spine to be amazing. There are over 270 monsters in the game, some share the same skeleton + animations, but I'd guess around 150 separate spine skeletons + animations just for monsters.
I was VERY concerned about performance due to having quite a lot of different monsters on screen at once, but I managed to use an atlas to share all their graphics and the game runs extremely well even on mobile, VERY impressed with Spine!
9th Dawn III is releasing in 6days on Steam, Nintendo Switch, PS4, Xbox One, Android and iOS on the same day. You can see a trailer here, maybe you can spot some other things I used Spine for (such as cooking minigame!):
Article with some history and features:
Massive thanks to Esoteric for this software. I'm using it for 2 other projects now aswell, I absolutely love it and its so much nicer to use than Unity animation!