Here is the full list of all 10 SokoWinter achievements.
Play with Stephen Coldy (Spheniscus Mendiculus)
Play with Harrison Frost (Aptenodytes Forsteri)
Play with Adele Pink (Pygoscelis Adeliae)
Play with Eddie Mullet (Eudyptes Chrysolophus)
Complete 20 Levels
Complete 40 Levels
Complete 60 Levels
Complete 80 Levels
Complete All Levels
Sleep a Little