Costa Vista

An open-world crime sandbox — street races, five-star chases, helicopter duels — coded by LLM agents routed through FastRouter.

fig. 01a — trailer — 41s, captured in-engine

Costa Vista is a playable open-world city on the coast: steal a car, run street races along the beach strip, pick a fight with the law, and watch your wanted stars climb until the helicopters show up. There's a working economy, a metro you can actually ride, day-night cycles, and rain-slicked neon streets after dark.

The interesting part is how it was built. The game was vibe-coded end to end by LLM agents talking to models through the FastRouter gateway — routing each task to the model that fits it, with fallbacks so a provider outage never broke the build loop. Gameplay systems, mission scripting, UI, and iteration passes all went through the same single API.

It started as a stress test: can a router-backed agent workflow ship something this big without hand-holding? The answer runs free in your browser — it drives around, shoots RPGs, and flies helicopters.

Field notes / screenshots

Costa Vista — arrival at Seabreeze Estates — fig. 01.1 — arrival at Seabreeze Estates

Costa Vista — street races on the beach strip — fig. 01.2 — street races on the beach strip

Costa Vista — taking on the law — fig. 01.3 — taking on the law

Costa Vista — owning the night — fig. 01.4 — owning the night

Costa Vista — bringing the boom — fig. 01.5 — bringing the boom

Costa Vista — helicopter duel over the docks — fig. 01.6 — helicopter duel over the docks

Costa Vista — five stars, full swarm — fig. 01.7 — five stars, full swarm

Costa Vista — neon getaway in the rain — fig. 01.8 — neon getaway in the rain

Costa Vista — boarding the metro — fig. 01.9 — boarding the metro

Costa Vista — leaving the city — fig. 01.10 — leaving the city

Build the next one.

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