Here is the full list of all 17 Obulis achievements. It takes around 10-12 hours to unlock all of the achievements on Windows.
Collect all 347 1/2 stars in the game.
Complete the level "Garden V Ultra"
Complete the level "Dark Forest III Ultra"
Complete the level "Pharaoh's Tomb VII Ultra"
Find all 3 tiles to complete the Blood Stone.
Complete the level "Antiquity XI Ultra"
Complete the level "Desert VIII Ultra"
Complete the level "Clock Tower VIII Ultra"
Complete the level "Pond III Ultra"
Complete the level "Dungeon V Ultra"
Complete the level "Pond X Ultra"
Complete the level "Pharaoh's Tomb I Ultra"
Complete the level "Waterfall XI Ultra"
Find all 3 tiles to complete the Earth Stone.
Complete the level "Gnarly Vines V Ultra"
Complete the level "Windmill I Ultra"
Find all 3 tiles to complete the Sun Stone.