I am surprised how good these biomes look w/ minetest_game, well done! This opens up numerous opportunities for adding new mobs to fit every biome (like crocodiles in the bogs, pandas in bamboo forests, etc), a lot of new exploring potential, and a lot of new crops/foods!
A few textures don't fit into MTG too well: namely bamboo and downy birch (and maybe cranberries should have a texture more like blackcurrants, it's hard to tell whether the texture looks like berries or not). This is really just my opinion though, everything looks quite good already.
Highly recommended, this is one of the best biome-adding mods for MTG I've seen so far!