Here is the full list of all 24 Fatrifice 2 achievements.
Lilith grew a size.
Lilith's clothes are getting tight.
Lilith is getting fat.
Lilith is more round than round actually is.
Lilith has become an ocean.
Lilith is beautiful.
Burp.
Recover from a burp.
Eat a total of 300 food.
Cook your first food.
Cook food 100 times.
Ruin some food.
Ruin some food by getting poop on it.
Upgrade the Immobile skill to max.
Upgrade the Foodie skill to max.
Upgrade the Chef skill to max.
Buy burgers.
Buy donuts.
Buy cupcakes.
Buy sandwiches.
Buy chub berries.
Play Endless Stuffing.
Lilith got as big as she can in Endless Stuffing.
Found the banana.