Climate

so basically, when you make a world, you could end up in any biome, a desert, a snowy taiga, a plains, anywhere,

So, what if you could, in world creation, set a climate? This changes biome rates. So if you set climate to "Temperate" you'd see more forests, plains, and overall temperate biomes. Whereas setting it to cold would spawn more Taiga, Snowy plains, and mountains