The Underrated Ambience Mod for Minecraft.
This is Nature's Spirit, a simple mod created to add more biomes and enhance world generation. However, simplicity doesn't stop this mod's atmosphere from being amazing, especially with the right shader settings.
Modrinth Download: https://modrinth.com/mod/natures-spirit
(Yes, I'm the guy who took the promo screenshots in the gallery section. Is this a promotion video? Nah, I just really like this mod.)