First 5 people to send in a correct set of guesses get an EP containing loads of alternative Figure Space/Minifigure/Tinyfigure tracks. There's 10 paintings in question whose origin games must be guessed. Here's a partial attempt:
Not sure what this is. NightSky? Clearly it was created somewhere around his "photorealistic" stage.
This is a secret from Knytt Underground itself.
Fire Nuclear Crocodile Killer. The Area 5 tileset, to be specific.
The pinball minigame from Saira.
No clue. I'm guessing this is one of Niff's more obscure games.
This is the hidden "Evil" minigame from Knytt.
A built-in photorealistic tileset from Knytt Stories.
This is the secret game from Within a Deep Forest that showcases all the unused creatures made for it.
That area from Mod Archive Story where the music notes attack you.
The credits area from MAS2: Operator Status.