Here is the full list of all 85 Slime-san achievements.
Beat level 26 in NG+.
Beat levels 21 to 25 in NG+.
Beat levels 16 to 20 in NG+.
Beat levels 11 to 15 in NG+.
Beat levels 6 to 10 in NG+.
Beat levels 1 to 5 in NG+.
Speedrun the entire 25 levels once!
Beat level 26.
Beat the scary dojo challenges 1 to 10.
Buy out the entire carpenter shop.
Beat levels 21 to 25.
Beat levels 16 to 20.
Beat the scary dojo challenges 1 to 5.
Beat levels 11 to 15.
Beat levels 6 to 10.
Buy 10 items in the carpenter shop.
Beat levels 1 to 5.
Go through the tutorial levels once.
Beat all normal and NG+ levels, collect all the Apples and beat all the Trophy times in World 5.
Beat all the achievements in Slime-san!
Beat a Speed Running Mode!
Beat a Boss Rush Mode!
Unlock and beat New Game PLUS level 101.
Beat the trophy time of level 101.
Beat all normal and NG+ levels, collect all the Apples and beat all the Trophy times in the game.
Beat all New Game PLUS levels in World 5.
Beat all New Game PLUS levels in the game.
Beat all normal and NG+ levels, collect all the Apples and beat all the Trophy times in World 4.
Beat all New Game PLUS levels in World 4.
Beat all normal and NG+ levels, collect all the Apples and beat all the Trophy times in World 3.
Beat all New Game PLUS levels in World 3.
Beat all normal and NG+ levels, collect all the Apples and beat all the Trophy times in World 2.
Beat all New Game PLUS levels in World 2.
Beat all normal and NG+ levels, collect all the Apples and beat all the Trophy times in World 1.
Beat all New Game PLUS levels in World 1.
Beat all levels in World 5.
Beat all the Trophy times in World 5.
Beat all levels in the game.
Beat all the Trophy times in the game.
Collect all the Apples in World 5.
Buy all pieces of clothing.
Unlock all arcade games!
Beat all levels in World 4.
Beat all the Trophy times in World 4.
Collect all the Apples in World 4.
Buy all shaders.
Buy all pieces of sideart.
Beat all levels in World 3.
Beat all the Trophy times in World 3.
Collect all the Apples in World 3.
Find grandpa-san in Slime town.
Beat all the Trophy times in World 1.
Beat all the Trophy times in World 2.
Collect all the Apples in the game.
Unlock and beat level 101.
Beat one target mode challenge.
Beat all target mode challenges.
Unlock one arcade game!
Buy one piece of sideart.
Buy one shader.
Buy one piece of clothing.
Buy all Playstyles.
Watch one cutscene in the settings.
Beat all levels in World 2.
Collect all the Apples in World 2.
Beat all levels in World 1.
Collect all the Apples in World 1.
Buy one Playstyle.
Look at one international leaderboard!
Listen to one track on any jukebox.
Talk to five citizens in Slumptown.
Beat all core sheeple levels.
Beat all core sheeple level trophy times.
Collect all bugs in core sheeple levels.
Beat all core sheeple levels in NG+.
Beat all remix levels.
Beat all remix level trophy times.
Beat the special sheeple level.
Beat the special sheeple level in NG+.
Talk to both hidden indie stars.
Get a high score in all 5 music game tracks.
Purchase half of the gallery.
Purchase all gallery sets.
Complete a speedrun of Sheep's Sequel.
Get the high score in Sheepleman 64.