Here is the full list of all 29 NEOMORPH achievements.
Kill 15000 Enemies
Date With Girl NO.4 2 Times
Date With Girl NO.4 1 Time
Date With Girl NO.3 2 Times
Date With Girl NO.3 1 Time
Date With Girl NO.2 2 Times
Date With Girl NO.2 1 Time
Date With Girl NO.1 2 Times
Date With Girl NO.1 1 Time
Kill 9000 Enemies
Kill 6000 Enemies
Kill 4000 Enemies
Kill 3000 Enemies
Stage 8 Clear
Kill 2500 Enemies
Defeat Boss
Stage 7 Clear
Kill 2000 Enemies
Stage 6 Clear
Stage 5 Clear
Kill 1500 Enemies
Stage 4 Clear
Stage 3 Clear
Kill 1000 Enemies
Stage 2 Clear
Kill 600 Enemies
Stage 1 Clear
Kill 300 Enemies
Kill 100 Enemies