This is a major mod that radically changes the survival mode in minecraft, it makes the mode more realistic and interesting. You will have to learn and develop and after that start building houses and castles.

The mod will change the generation of the world, the game will not have the usual game biomes, they are all significantly reworked, especially underground.
The mod replaces the system of lives, damage, hunger, experience and adds a thirst system, all these systems are interconnected, the parameters can change during the game, decrease or increase. The damage and health of mobs makes it impossible to kill monsters with bare hands.

You will have to take care of your health, not be fat, eat enough proteins and vitamins, monitor your thirst and temperature.

The mod adds a system for changing the seasons, the world will change depending on the season, the game will have real time and a year on which a lot depends, for example, which crops grow well.

The crafting of many items has been completely reworked, a stone ax needs to be created from stone, using a special craft, and all others using an anvil.

The physics of many items, now you can't build a house out of mud or other loose blocks, the mud will just fall down, you can only build a pyramid out of mud.

Water can be salty or fresh, grown vegetables and fruits can be of different ripeness and size, food can go bad, and much more.