Here is the full list of all 11 Snakebird achievements. It takes around 6-8 hours to unlock all of the achievements on Windows.
Complete every single level
Complete the final level
Complete all levels on the Temple tileset
Find all the clickable props
Complete all levels on the Space tileset
Complete all levels on the Ruin tileset
Complete all levels on the Ocean tileset
Complete all levels on the Island tileset
Complete all levels on the Winter tileset
Collect one of each fruit
Die once with every snakebird