@moxie Etherdoek is a very similar project, also stores all pixel info on chain (Ethereum), which are tradable as NFT's. It's a 1,000 by 1,000 canvas. etherdoek.com
Many have asked about the high price to mint pixels. It does not go to me; it's locked in the contract that everyone w/ pixels "owns" a piece of (to prevent land grabs).
One hypothesis is that art hasn't emerged b/c of the price, though, so I lowered it to 0.036 eth. Have at it!
I made another collaborative art NFT: popularpixels.art
Unlike Autonomous Graphics, this NFT is composed of 400 pixel blocks that are each 50x50px. Once a pixel block is claimed, only the owner of the pixels can edit them. The blocks all combine to form the whole image!