Level 6 (Ending 3)
Back to The Talos Principle
To reach the third ending you’ll need to find all 30 Stars and complete the 3 star worlds to find the 9 Grey Sigils. This essentially completes everything in the game.
Inside each of the Star Worlds you’ll see a sign that shows one number of the 3-number code to unlock level 6 in the tower. These are random every time so your game will be different than mine.
Go to one of the terminals in the tower and unlock Level 6 using the code. Return to the lift and ride it to level 6 which is actually inside the basement of the tower. Once inside you’ll have one final sigil puzzle to complete.
Head into the portal and take your place as one of the eternal messengers. Congratulations on completing The Talos Principle!
Back: The Tower (Ending 2)