How to unlock the "Items Descriptions" achievement

The pause menu got shrinked and moved to the bottom of the screen.
It also came with a new section called "My stuff".



Once you open it, you can read your items' description.

The new "My Stuff" section can only be unlocked when defeating Mom (the foot) for the first time.

That means that if you want to get the achievement you just need to do a run and beat Mom once, at least that's how I got it.

Sadly, that won't be the case for everyone, since there's more to it...



This is official news from Edmund McMillen that states that you also have to collect every item at least once to unlock every description and, probably, also the achievement.

Indeed, most of the people that managed to get this achievement, already had Dead God.

Also, this achievement is probably only obtainable in Repentance+.

All of this is only hypothetical, at least for now.
There is still mystery around the achievement and how it actually works but this is all I have for now.
This is the most trusted way you can choose to get the achievement, but it's not 100% guaranteed.

I hope this helped you guys, have a nice day! :D