>>721415Sora no Woto is a very nice and comfy slice of life with an interesting setting and a plot that grows in the background; a true hidden gem.
Shoujo Shuumatsu is a little like Sora no Woto, only both the moe and the setting cranked up to 11.
Made in Abyss is a very cool and visceral adventure. I recommend getting into the manga too, as it's very well drawn and goes way further than the anime did.
Houseki no Kuni is really good, if you can stomach 3D animation. The worldbuilding is pretty neat, the characters are really well designed and fleshed out, and the animation is very good at times.
Kobato is another super cute and comfy one to consider, too. It's a sweet story with a satisfying ending.