I realize that this question might have been asked already, but I searched several sites and wikis, but I could not find out.
Why is the Platinum God not unlocking for me?
I did everything, except the unlocks for the Lost. I have got all other achivements and I also picked up all items, except some Lost items (I got some Lost items, because of a D4).
Pictures showing my progress:
(I can only post two links, the first two item pages are complete)
I got all challenges, have done everything with all characters (except the Lost) on normal and beat Moms Heart on Hard. I unlocked all endings and also beat Mega Satan and I'm playing on PC.
This should cover everything and I still didn't unlock Platinum God (not the real Platinum God, I'm not that crazy yet!) and I'm kind of out of options. Does anyone have a solution? (I restarted the game several times, did more runs, beat Mega Satan again, but still nothing).
Best Answer
The item you are missing in the sixth row of the first page you showed is Missing No., which is unlocked by beating Boss Rush with Lazarus.
The wiki has a Collection Page page, which shows what item would go in each slot of the collection page.