How to make a game with Claude Opus 5.5: workflows, costs and limits

Most are 3D browser games modelled on a well-known genre. Shooters, action and open-world driving lead, followed by sims, remakes, racers and voxel sandboxes. About three in ten own-build posts link a playable version.

Sample/method: Sample: posts where the poster says they built the game; genres from an AI first pass, about nine in ten right on a spot check.

In a rough AI count, 143 of the 488 own-build posts gave a link or repository to play.

David Walter (@davidpwalter) had Opus build a Godot game in 30 minutes, then remake it as real Game Boy Color, Game Boy Advance and N64 ROMs. Danny (@itsdannyyt) got Crab Dash (6 levels, a level editor, original art and music) from one prompt after 2.5 hours. yurshev (@yurshevv) reports a GTA-style city in a single HTML file in 17 minutes.

Livsun (@L1vsun) posted this NEON BAY cover on 30 September 2026. The builder says Opus 5.5 made the GTA-style city in 2 tasks and 1h 46m of build time. The image shows the setting, not how well the driving plays. (Item: Claude Opus 5.5 builds GTA-style 3D city NEON BAY in under two hours)

On Roblox, Stravant (@Stravant) made "Crossroads RTX ON" with Opus in 3 hours, using up to 10 subagents at peak. Min Choi (@minchoi) gave Opus one game idea before bed and woke up to about 11,000 parts. Getting the game to be fun took another week of building with the kids.

Mods of existing games are another large group. Superintelligence Gaming Factory (@sigf_ai) turned Minecraft into a Fortnite-style battle royale in 65 minutes with one Opus agent. Mods like this depend on the original game's files.

For a prototype, start with a single three.js HTML file. Move to an engine through MCP when you need real assets and physics at scale. Multi-agent loops suit long, expensive projects.

A single browser file (three.js or WebGL) is the most common route: nothing to install and one link to share. eric, Tony, Livsun and Luneri (@itsluneri) all shipped browser builds.

To use an engine, Claude connects to it through MCP. Jan (@jan_volad) used Godot, Blender MCP and free CC0 textures and sounds on the $20 Pro plan. The first playable version took 3 hours, and Opus also wrote tests that play the game through to prove it can be beaten. Ruben TORNEY (@RubenTorney) ran one /goal prompt through the UE 5.8 MCP for 36 hours. Hakimi Eiqbal (@hakimieiqbal) spent a full weekly Opus limit on Blender MCP and Unity 6.

Ruben TORNEY (@RubenTorney) posted this cover on 2 October 2026. The builder says one /goal prompt ran for 36 hours to make the 2 km × 2 km map. The post also lists what still needed fixing (see the limits section). (Item: Opus 5.5 builds a playable open-world game in a 36-hour run)

The multi-agent route adds play-testers. Luckey Faraday (@luckeyfaraday) built a 30-player browser shooter with 438 subagents in separate git worktrees. Fresh-context reviewers played every build, scored it and sent it back. The first playable came in 26 minutes; after about 72 hours there were 314 commits, 2,223 screenshots and 2.46B tokens, and the builder said it was still not finished. Mr Tactical's Among Us clone used 98 agents.

Mr Tactical (@MrTacticalX) posted the Among Us clone video on 17 October 2026. In this frame at 1:10, a player named Opus says "Ziggy is sus" in the meeting chat. It shows the social round working, not the whole game. (Item: Among Us clone built by Opus 5.5 with 98 agents and $972 in API usage)

Many builders add outside 3D tools such as Meshy, Tripo or Blender MCP for characters and props. Max (@maxt3chno) imported a boat, a weapon and a bed made in Meshy.

Nine of the 16 priced builds cost $100 or less, and the $500+ builds were long runs. On a plan, a small game used a slice of the weekly quota and a big one could use most of it.

Table: Claude-built games with a dollar cost (self-reported)

Sample/method: Sample: the 16 builds with a dollar figure among 161 hand-read posts about the poster's own game with a cost or time. Opus 5.5 unless noted; costs mostly API-price equivalents, self-reported, not re-run by us.

Sample/method: Sample: 16 hand-checked builds of the poster's own game with a dollar cost; mostly API-price equivalents, self-reported, not re-run by us.

Table: Building games on a Claude plan: weekly usage the builders reported

Sample/method: Sample: hand-read builds that reported plan usage rather than dollars; percentages are the builders' own figures, not verified.

Effort level matters. Tak (@cherry_mx_reds) had Opus 5.5 build 3D Sonic at all five effort levels and played each one. Low took 9 minutes and barely tested its own game. Max took 2.5 hours, most of it testing and fixing, and was the most playable of the five.

Tak (@cherry_mx_reds) posted this test on 28 September 2026. The cover names the five levels (Low, Medium, High, XHigh, Max) used with the same prompt. (Item: Opus 5.5 builds 3D Sonic at all five effort levels, from 9 minutes to 2.5 hours)

On official pricing, Opus 5.5 costs $4 per million input tokens and $20 per million output tokens, and Sonnet 5.5 costs $2 and $10. Sonnet can build games too. YFarmX (@YFarmX) made a 3D orchestra game for about $35 on Sonnet 5.5, and Danny Limanseta (@DannyLimanseta) gave Sonnet 5.5 full artistic control of an action/puzzle RPG made in a couple of days. To compare the three tiers, see our Opus vs Sonnet vs Haiku article.

Builders who shipped playable games wrote the loop and the rules first, built one mechanic at a time, and had Opus play and fix its own build.

dunik (@dunik_7) built a CS surf game in eight stages. First, write GAME.md with the feeling, the loop, the numbers and the rules. Then build movement only, with sliders for speed, gravity and air control. Add one map. Let Opus open the tab, play it and fix what feels wrong. Then add the extras, a leaderboard and ghost runners. Ship it as one index.html.

Semichenko (@semichenkko) made a $17 No Man's Sky-style prototype and stresses a tight brief: what the player does, what the ship can do, and what breaks the magic if it loads. Their advice: "Write the loop first."

eric (@ericmaskfr) posted this gameplay on 29 September 2026: a first-person shooter in the browser with a minimap and an ammo counter. The builder says it took 3 prompts. (Item: Three prompts build a Call of Duty-style shooter with Opus 5.5)

Self-testing comes up again and again. Jan had Opus write play-through tests, Luckey Faraday's reviewers played every build, and Tak saw Max effort spend most of its time testing.

Tony (@EnvolDev) posted this title screen on 29 September 2026. The builder lists 4 tracks, 8 racers, 9 items, drifting, AI rivals and a Grand Prix, and links a free version to play. (Item: One prompt gets Opus 5.5 to build a Mario Kart-style game)

Copy the feeling, not the assets. dunik's rule is to copy the feeling of CS surf, never its maps, names or sounds. Many showcase posts clone commercial games. Publishing a clone raises legal questions this guide does not cover.

Characters and animation, physics edge cases and long-run cost are the usual failure points. A one-shot is a prototype.

Animation is the weakest area. J A Z I I (@notjazii) asked Opus 5.5 to add animations, and after 5 hours it kept breaking the character. They stopped and built a different game.

Physics and polish lag too. Ruben TORNEY's UE 5.8 one-shot had floating stones and flowers, some collisions with the environment, VFX that needed work and a weak character body. Zach (@ZryMiller) said their zombie game took about 12 hours, was "by no means a one-shot" and still had rough edges.

3D models are another trap. Building a 3D wuxia ARPG, cnyzgkc (@cnyzgkc) spent two days just finding a modelling route. The AI-generated models had messy topology and broke once rigged, until the builder switched to a model tool that outputs quad topology.

Long runs can get expensive: $2,550 over 47 hours for Stefan 3D AI, about $1,200 for Amay (@AmaySignedIn). Set a budget or a plan cap before a multi-hour run.