How can Minecraft-like games become scalable cloud services? Hundreds of Minecraft-like games, that is, games acting as modifiable virtual environments (MVEs), are currently played by over 100 million players, but surprisingly they do not scale and are frequently not published as cloud services. We envision a new architecture for large-scale MVEs, supporting much larger numbers of concurrent users by scaling up and out using serverless technology. In our vision, developers focus on the game (business) logic, while cloud providers manage resource management and scheduling (RMS) and guarantee non-functional properties. We provide a definition for MVEs, model their services and deployments, present a vision for large-scale MVEs architected as serverless systems, and suggest concrete steps towards realizing this vision.