Here is the full list of all 76 Duet achievements.
The base game contains 66 achievements, and there is 1 DLC pack containing 10 achievements.
Beat "continuance" wave 1000.
Beat all of "transcendence" without hitting a wall.
Beat "continuance" wave 100.
Beat all of "resilience" without hitting a wall.
Beat "continuance" wave 10.
Beat all of "integrity" without hitting a wall.
Beat all of "release" without hitting a wall.
Beat all of "acceptance" without hitting a wall.
Beat "transcendence".
Beat all of "perspective" without hitting a wall.
Beat all of "tension" without hitting a wall.
Beat all of "ambition" without hitting a wall.
Beat all of "anticipation" without hitting a wall.
Beat all of "quickening" without hitting a wall.
Beat all of "revolution" without hitting a wall.
Beat all of "intimacy" without hitting a wall.
Beat all of "initiative" without hitting a wall.
Beat all of "identity" without hitting a wall.
Beat all of "control" without hitting a wall.
Beat all of "understanding" without hitting a wall.
Beat all of "trust" without hitting a wall.
Earn at least 1500 in infinite mode.
Beat all of "hope" without hitting a wall.
Beat all of "depression" without hitting a wall.
Beat all of "guilt" without hitting a wall.
Beat all of "bargaining" without hitting a wall.
Beat all of "anger" without hitting a wall.
Beat all of "denial" without hitting a wall.
Beat "resilience".
Beat "quickening".
Beat "revolution".
Beat "release".
Beat "perspective".
Get at least 750 in infinite mode.
Beat "tension".
Beat "ambition".
Beat "anticipation".
Beat the game and watch the end sequence credits to the end.
Beat "integrity".
Beat 100 daily challenges.
Beat "intimacy".
Beat "initiative".
Beat "identity".
Beat five advanced daily challenges.
Beat "control".
Beat "understanding".
Beat "trust".
Beat "acceptance".
Successfully navigate invisible blocks.
Beat "hope".
Beat "depression".
Beat ten daily challenges.
Beat "guilt".
Beat seven daily challenges in a row.
Beat "bargaining".
Beat three daily challenges in a row.
Beat one daily challenge.
Beat "anger".
Get at least 250 in infinite mode.
Try the infinite mode.
Beat "denial".
Fail 10 times in a wave before completing it.
Beat all of "ignorance" without hitting a wall.
Successfully spin around a rotating block.
Beat "ignorance".
Beat the first wave.
Beat all of "reintegration" without hitting a wall.
Beat "reintegration".
Beat all of "reunion" without hitting a wall.
Beat "reunion".
Beat all of "resentment" without hitting a wall.
Beat all of "relief" without hitting a wall.
Beat "resentment".
Beat "relief".
Beat all of "confusion" without hitting a wall.
Beat "confusion".