IF YOU DON'T WANT TO SURVIVE IN A PURELY WINTER WORLD BUT STILL WANT THESE MODS, CHECK OUT 'The World Horrors Project.'
OUTDATED DESCRIPTION BELOW. DESCRIPTION WILL BE UPDATED SOON.
Start out in a cold, unforgiving winter. Why? Becuase I don't like you, I don't know? I'm not one for storylines.
All you got is a gun with 51 bullets, steak, a lantern, a flashlight with one extra battery, some heating things, blah, blah, blah, point is, you don't have much.
What's your goal? Dunno, didn't think that far... but I suppose surviving 100 days would suffice.
Daytime, bad. Nighttime, even worse. Get a base as soon as possible or you are f█████.
There's also true darknes, I mean, look down here.

Look at that. Can you tell where I'm facing? Hell no. You're welcome for that flashlight and lantern.
[IN THE LATEST UPDATE OF THIS MODPACK, THERE IS NO DEFAULT TRUE DARKNESS. YOU WILL HAVE TO GO INTO YOUR VIDEO SETTINGS IN-GAME TO ENABLE IT.]
There's also two shaders you can pick from.
A VHS/Retro style one, like the one in the previous image, or a modern looking one.
Most shaders don't work with the true darkness, so either find one that does, or you're limited to those two.
Here they are by comparison in a cave (a lantern is at my feet; typically, unless there is lava or something, caves will be pitch black asides from ores):

Oh, yeah, if you didn't read the summary, all you get is 10 lives. You lose a full heart every death. Goodluck!