Shameless plug - and nothing so grandiose as SimCity but I built a pretty substantial 2D/3D blindfold trainer chess game. It's by no means "vibe coded" though, and there's a fair bit of manual work around the 3d modeling that I had to roll myself.

Even with that I'd still say 70% of the code was written using LLMs with the opencode agent.

https://shahkur.specr.net