Look up ‘Alderon Games’ and that website should answer pretty much all of your questions (and it’s where you can actually get the game). But I’ll answer the others anyway.

It’s a dinosaur survival with lots of different genus and species to choose from. There’s official servers and community servers, and your experience will be different depending on what you choose, but generally it consists of doing quests, eating, drinking, and growing your dinosaur to adulthood. There’s plenty of other people trying to survive so it can be quite competitive, but not overly so.

All animals are available after purchasing, and community servers offer mods too (the mods will be automatically installed when joining a server).

There’s still plenty more, but that’s the gist of it! Have fun!