The Sheep's Medieval Config

This modpack embodies the humble, yet enticing, medieval ages- in a way that creates a challenge out of pure realism. This modpack is for those who like to play the game slow, though, this mod will surely force you to play in that manner. And for players who wish to quickly loot your way to the top, good luck! (as that may not be ever so easily possible). 

A series of mods and features will hinder your progress in a way that feels natural:

• Players no longer move from stone to iron. With Progression Reborn, we significantly hinder the process of moving from stone tools to iron, adding a middle man: copper! Copper, slightly faster and more durable than stone, will serve as your starting companion in the game. Stone will also probably be heavily utilized until you unlock a more durable and efficient iron. This mod also adds the feature of raw copper and iron nuggets, further complicating the process involved with transitioning to iron. 
• One of the earliest threats-and honestly, an annoyance-that you'll encounter is the need to drink water. Simply guzzling the water out of the river beside you will not cut it. When starting, prioritize obtaining sand to make glass, which will then aid you in creating bottles and starting the purification process(cooking water on campfire or furnace). Make sure that your water is completely purified, or there will be consequences! 
• If replenshing thirst wasn't enough of an inconvenience, we got you covered! The Cold Sweat mod, a mod designed around adding realistic temperatures to the game, will have you looking for lit furnaces and campfires in no time(or maybe even a relaxing pool of water). Track your temperature and stay in the temperate zones, using your resources to weave your armor into combatants against the harsh conditions. Hopefully your efforts will be good enough for the winter season!
• That was a perfect segway into our next challenge, seasons! Not only will Serene Seasons affect your ability to stay warm or cool, but it will affect your crop growth and rain cycle. Funnily enough, I would not brush off pretty spring storms.
• With weather conditions being so bland in the base game, I have decided to add wind of all things to help spice things up. Wind is a constant phenomena which grows worse as the weather does. This wind will push not just you, but any and all entities, including mobs, arrows, and falling objects. This feature may sound harmless, but let me tell you, it's one of the most hated mods in this whole modpack.  
• This feature has been removed.
• And if all these natural changes are not enough for you, have fun with your fellow enemies across the world! You may not loot villages because they love policing, and you may not loot castles because just about every kingdom is heavily armed and ready to attack, and you may not befriend pillagers as they are so insanely buffed that you will make a fool out of yourself if you dare, BUT you MAY start your own kingdom to fight against iron weilding, horse riding, ballista shooting empires, of all human, zombie, pillager, and skeleton species; of course, when you reach that point. And it may be a while before you can do much at all, so I'd be as neutral as I could. 

I could continue my list of heavy hitting mods that are sure to slow your progress in the game; however, I think that presenting this last one will make the rest look minimal. 

I have added the mod: Reskillable Reimagined, which sounds like what it is. This mod adds leveling to the game, and, oh sure, it may not be all so realistic, but I am sure this will slow you down. Just about every weapon and piece of armor has been configured to this mod, making it impossible to progress without it. And with this mod, I have enforced the majority of your playing time to be focused on the iron age, for you to focus on building and such. You will gain buffs from this mod, but don't expect much. 

Of course there are a series of more mods in this modpack, such as Create, Cataclysm, Valarian Conquest, Simplyswords, Farmer's Delight, Physics Mod, Eureka! Ships!, and much much more. However, I feel the need to emphasize the slowed progression of this mod because that is simply is my favorite part. If you are someone who enjoys playing slow and growing a connection to your world, I highly recommend this modpack.