Naughty Dog “surprised no one has [found] the secrets we’ve dropped around the internet”

[GribbleGrunger]

FatedReality said:

What were the easter eggs in the costume shop? And what is the secret door?

A drakes costume and a Jak costume, but if I was to make a guess, I'd go looking on the Facebook pages they show in the Pharmacist, and yes they actually DO exist.