Here is the full list of all 24 Fork Knights achievements.
Finish your first round
Beat the tutorial
Win 50 rounds as Serious Ham
Win 50 rounds as Frank
Win 50 rounds as Choi Boi
Win 50 rounds as Fineapple
Win 50 rounds as PoshMello
Win 50 rounds as Fungai
Win 50 rounds as Mean Streak
Win 50 rounds as Fondude
Win 50 rounds as Dough Boi
Have 90 characters get knocked out of the stage
Have 30 characters burn in the kitchen level
Hit 100 enemies when they are down
Have 115 characters get knocked out by stage hazards
Finish 2 games of Fork Knights
Have anyone fall into the water 10 times
Finish 10 rounds on the bamboo level
Get cooked 40 times
Finish 10 rounds on the grill circle level
Hit with a long range skewer
Have a fireball reach an insane speed
Bounce on 4 bubbles without hitting the ground
Have 4 bananas deployed at the same time