The Binding of Isaac: Rebirth

Unlock Lilith

This is a fairly simple achievement (bugged for me). All you need to do is beat greed mode with Azazel, which isn't too hard, just get items that increase your range and tear speed, as well as get yourself some room based abilities and items, such as the shears or the book of belial, as they will help for that room, up until you leave that room. So just use it before you press the button, and just make sure you don't leave the room at all, until you have completed all the waves, then go through the devil/angel room (if you don't go here first, the room will disappear upon leaving to another room) then head up to the shop and buy everything you personally like. Just continue doing this throughout the floors until you go up against Ultra Greed (one of the new bosses in this DLC)
Now this boss may be slightly challenging for new approachers, so there are some tips for you:
He spawns some keepers on the ground when he stomps
He will charge at coins that are dropped to pick them up
He will charge at you when you get in his line of sight
When he starts spinning around, keep your distance, because he will start throwing coins around every where
When his eyes start spinning like a slot machine he will stand still, which is a great time to attack or finish off some minions
-If his eyes land on two different symbols, he will spawn some giant spinning coins that WILL do damage to you if they hit you
-If his eyes are bombs he will spawn a bunch of bomb coins, which will eventually explode, dealing damage to anything it hits (or heal you if you have pyromaniac). Touching the coin will NOT hurt you, the explosion will, so if you have E coli, you can turn the coins into poop.
-If his eyes are keys he will spawn key coins, after a short while the keys will unlock doors that will send in hordes of keepers that will charge you, try destroying the coins as quickly as possible, unless you have something that gives health or something on killing enemies. Touching the coin will NOT hurt you, the explosion will, so if you have E coli, you can turn the coins into poop.
-If his eyes land on hearts he will spawn a bunch of heart coins, which will eventually heal him for each coin left remaining. This one isn't too bad, because the amount of healing isn't too extreme, and they are easily destroyable. Touching the coin will NOT hurt you, the explosion will, so if you have E coli, you can turn the coins into poop.

This achievement might be bugged, but if its anything like the achievements that were bugged before, they will be fixed and the achievements should be given to you on the next update.

-Update. (Thanks to Sakori for this) if you go to your secrets, all bugged achievements will be unlocked, just takes a couple of seconds.