Basebuilding/dungeon crawling/pixel art/roguelike. Kinda like ADOM meets stardew, but weirder and more Japanese. Weirder how? Here’s the wiki entry on the chaos shape race, which you can play as.
VERY in depth systems in the game. Mutations, crafting, prayer, it’s a deep game.
Star Wars Galaxies was such an ambitious MMO at launch.
Crazy in depth crafting system, especially with regards to pets. With how materials were randomly generated and cycled out it created a market that actually experienced booms and scarcity.
Some of the servers went almost a year before all the materials required for certain weapons spawned. And the materials all had random stats that would affect the item you crafted.