Here is the full list of all 30 Dr. Fetus' Mean Meat Machine achievements.
Finish World 01.
Finish World 02.
Finish World 03.
Finish World 04.
Finish World 05.
Finish World 06.
Trigger 1 Evolution.
Trigger 3 Evolutions
Trigger 5 Evolutions.
Trigger 7 Evolutions.
Trigger 9 Evolutions.
Trigger 11 Evolutions.
Evolve the real Super Meat Boy.
Do a 2-Chain.
Do a 4-Chain.
Do a 6-Chain.
Kill more than 200 Super Meat Boys in the Credits.
Kill less than 15 Super Meat Boys in the Credits.
Do 100 pops.
Do 500 pops.
Do 1000 pops.
Try a level more than 10 times.
Try a level more than 50 times.
Try a level more than 100 times.
Get the A+ Rank on all Levels in World 01.
Get the A+ Rank on all Levels in World 02.
Get the A+ Rank on all Levels in World 03.
Get the A+ Rank on all Levels in World 04.
Get the A+ Rank on all Levels in World 05.
Get the A+ Rank on all Levels in World 06.