Not really an easter egg, but something to look for in Episode 3.
Check out Max's mouth after his death monolouge as he is trapped in the Teddy Bear machine. As the pressure builds up, his mouth slowly gets streatched to the sides as if he is really stuck by his head!
It's those little things that I tend to appreciate the most. Kudos to whoever did that!
Also, I finally beat the Wack-da-Ratz game at the highest speed with no mistakes, but nothing happened. What gives?