1. Introduction of TFOC This is a follow-up note on the progress of supporting trustless browser game developpment in web3. (The initial work is presented at https://www.youtube.com/watch?v=dLZbfTWLGNI with notes available on https://delphinuslab.com/wp-content/uploads/2023/04/zksummit-presentation-zkwasm-game-1.pdf) With the further development of web3, fully onchain games have once again come into our view. They claim that they are better in Decentralization, Transparency, Trustless and Community Governance. However, FOC games also inherit the blockchain’s dilemma regarding Decentralization, Security, Scalability. That implies the difficult task of balancing game content, interactive frequency, decentralization, trustless and community fairness are the thorny issues of game developpers in FOC narrative. Thus, ages ago, game developpers compromises the architecture and introduced a best practise architecture which is broadly referred as web2.5 game architecture. More precisely, Web2.5 is a catch-all term referring to a blend of web3 and traditional games. Web2.5 emphasis on the contents of the game play since the believe that the main audience of the game is still rooted in web2. Meanwhile, they add the ingredients of web3 (NFT, tokenomics, play to earn) to their games so that their game can stand out. A standard web2.5 game architecture might looks like the following: