Buildings games in Unity feels like magic with frontier reasoning models.
Assuming you are competent with scene work and the various art pipelines, the rest of the problem is significantly easier now.
I've been using the Unity CLI to run arbitrary C# code against Unity 6 scenes without requiring domain reloads. It uses Roslyn to compile the snippet in a special Unity editor component instead of running the normal compilation pipeline.
The implications for a reasoning model are significant. Domain reloads in my projects can take 10-20 seconds. Compound across 5-10 tool calls and the difference adds up very quickly.