Fear is a game mechanic when you're in the dark.
In goes up by thirty in-game seconds in the dark, and down when in the light.
Bad things could happpen if fear reaches 25, 50, 75, or 100%.
Bad things at 25%
You go to the alternate dimension, the Tarr Dimension. All slimes are tarrs.
Bad Things at 50%
Too much Speed!
You go really fast, and CAN fall into the slime sea.
Bad Things at 75%
Your screen goes near black and Tarrs pop out at you
Bad Things at 100%
You go back home to start a new day
Good Things at 25% - 50%
You unlocked: Forbidden Slimes!
Good Things at 75%
You unlocked the Dark Lands.
Good Things at 100%
You now unlocked Scareslime V2.