Here is the full list of all 25 Slime Masters achievements.
Survive without moving
Survive without leveling up
Kill 1000 monsters of any type
Kill 10 000 monsters of any type
Kill 1 000 000 monsters of any type
Kill 1 boss
Kill 100 boss
Kill 10 000 boss
Dip a slime in a colored pool
Dip your slime in a colored pool 100 times
Dip your slime in a colored pool 1000 times
Dip your slime in a colored pool 100 000 times
Have a total of permanent power-up of 5
Have a total of permanent power-up of 25
Have a total of permanent power-up of 50
An hour of playtime
A day of playtime
A week of playtime
A month of playtime
A year of playtime
Pick-Up the collectables and carry it to it's master
Pick-Up the experience orbs and carry it to it's master
Heal the player every X seconds
Slime that attack the closest monster
Slime that attack the monster with the highest HP