Hardercraft is a mod that will make Minecraft a lot harder.
The first thing you will notice is that dirt no longer drops it's block.Instead it now drops about 2 dirt balls. This a new item. If you have 4 of them you can craft a block of dirt.
The next thing most people do is collect some wood. This is impossible now. You will have to destroy a leave that now drop sticks. You also need to collect some sand. Sand now drops sand balls.
You need 4 sand balls to create a sand block like this.
If you combine 3 sandstone (crafted with 4 sand each) and a stick and combine them in a crafting table like this you get a machete. It is a very slow and weak tool that will allow you to harvest wood. With the wood most people want to make a crafting table, some wood, sticks and maybe also later torches. All these recipes have changed now.
Now you can craft a wooden pickaxe. They are just like the stone tools a lot weaker and slower. When you use them on stone they also don't drop the block, but about 3 rocks.With 9 of these you can create a stone block like this.
Sheeps no longer drop wool. Instead they drop string now. You also need 9 string to make 1 wool.