Here is the full list of all 15 Cubytet achievements.
Score 1000 points at any difficulty level
Score 1000 points on a hard difficulty level
Score 2500 points at any difficulty level
Score 2500 points on a hard difficulty level
Score 5000 points at any difficulty level
Score 5000 points on a hard difficulty level
Fill one panel with cubes
Fill two panels with cubes at the same time
Fill three panels with cubes at the same time
Fill four panels with cubes at the same time
Place a piece on the playing field 2000 times
Fill 50 panels with cubes
Add 250 cubes to the pieces
Achieve a speed of x3.0