Here is the full list of all 21 Sokoball Dreams achievements.
Win Level 5
Win Level 5.2
Win Level 10
Win Level 15
Win Level 20
Win Level 29 A
Win Level 29 B
Win Level 29 C
Win Level 30
Win Level 35 A
Win Level 35 B
Win Level 35 C
Win Level 46
Win All Levels
Win All Levels on Minimal Moves
Push 10 Boxes
Push 100 Boxes
Push 250 Boxes
Push 500 Boxes
Push 750 Boxes
Push 1000 Boxes