Ratchet & Clank (2016) | Secret Insomniac Museum
When you complete the game you get access to the Insomniac Museum which is a collection of 6 warehouses filled with weapons, videos, pictures, and all kinds of memorabilia from the entire Ratchet & Clank franchise. I didn't play all the videos in the 2nd warehouse as they were repeats and spoilers from the game . . .
You need to gather all 28 Golden Screws hidden throughout the game in order to access all 6 different warehouses, but it's not too taxing to find them : )