Antimatter Elevator
2 Achievements
Steam
Perfect Ending
63.7%
How to unlock the Perfect Ending achievement in Antimatter Elevator - Definitive Guide
Finish the game with no blocks left on the board, the easiest way I found was to keep a black and a white block in the bottom left corner to hold those two rows until those are the final 2 blocks and only work in the third row for the rest of the game.