This page is a collection of every easter egg that has been discovered.
Level 1: An Awakening
Genji's sword from Overwatch
There is Genji's sword from Overwatch in a burning barrel. It is located in the first zone where you face 3 enemies. First, take the slope, and the sword will be to the left, in a small corner.
Level 2: A Look Inside
Aku from Samurai Jack
Right at the beginning of the level you can see a small light in the tower in front of you. The goal is to get to that light by wallrunning and jumping. When you're there, you can see various objects positioned in a specific way that cast the shadow of Aku, the main antagonist of the series Samurai Jack. This can be linked to Ghostrunner's protagonist having the nickname Jack, and the use of samurai swords in the game.