Secrets in BP???

[Thaliur]

You mean the artifacts? I found them all. And notes also. But the eastereggs.... that sounds quite silly for me

I think I sense a misunderstanding here.
No one here is talking about actual easter eggs. The term Easter Egg is just a metaphor for hidden, mostly funny, stuff in games, movies or other media. Often these are a kind of pop culture or historic reference.

Some examples?
The "Uncle Cthulhu's Squid Soup" can, and the crowbar with the name "Freeman" on it in Overture.