Just Enough Suffering
This mod turns Minecraft into a true nightmare by adding numerous annoying mechanics that will make your gaming life unbearable.
Among its "delights" you'll find:
Workbench with a surprise - every time you place a crafting table, a puddle of lava magically appears on it. Crafting has become even more dangerous!
Night visitors - every 2.5 seconds during nighttime, a phantom appears above your head. Your favorite mob will now accompany you constantly!
Exile to detention - for certain actions (such as attacking passive mobs), you'll be sent to a special punishment dimension where you'll have to serve "timeout".
Questionable accessories - a collection of useless trinkets like the lava backpack that periodically douses you with molten rock.
Clumsiness - while sprinting, you can trip, which slows your movement and causes damage.

Enjoy the suffering!