I added Co-op online to Lazy Blocks.

Using PeerJS & WebRTC, so no server.

Hope you enjoy, let me know if you have and feedback, etc.

Thank you, Adam

-- EDIT

Oh! -- Click the "Globe" icon to start online play

-- Edit 2

Oh! -- I should mention - the board is infinite, you can scroll and pan and zoom in all directions -- and you can always find the other player with one click