The problem
How it works
Alex Finn’s 35-minute video starts from one prompt, given in full in the description, for a third-person roguelike in Unity in which a sword-wielding player fights demons and picks up weapons, skills and buffs on levelling up. The prompt deliberately asks only for a first vertical slice: demons spawn, the player can kill them, and the sword combat feels satisfying with good animations and combos. The chapters then follow the build: the first slice, rounds of gameplay changes, better graphics, testing new assets, a push toward polished visuals, and final playtests.
Results and limitations
Marked reported: the creator shows the game being built and played, but the description gives no build time, cost or code size, and the result is a prototype slice, not a finished game.
Before you try it
The transferable idea is the small vertical slice: it gives the agent a goal it can finish and gives you something you can judge by playing it. Check the licences of any generated or downloaded art, models and sound before you publish. Commit after every working change so a bad edit to scenes or prefabs can be rolled back. Results depend on your setup and were not independently reproduced by Top 200 Repos.
Tools and repositories
- Tools
- Claude Code · Unity
- Prerequisites
- Unity installed locally and a Claude plan that includes Claude Code.
Try it yourself: Scope a vertical slice before building
Fill the fields to adapt the prompt. Empty fields stay as visible [placeholders].
I want to make a [Genre] game in [Engine]. Before writing code, define a vertical slice I can play in one sitting: [Core loop]. List the scenes, scripts and placeholder assets you will create, how I will test that it feels right, and what is out of scope for now. Then build only that slice and tell me how to run it.Play the slice yourself after every change and describe what feels wrong in plain words.
Related videos
About anthropics/claude-code
You Can Turn Obsidian Into JARVIS (Claude Code) Anyone Can Do This (opens in a new tab)
Walkthrough of claude-code by Maitis: the title names the project; the description links the project website.
Watch on YouTube (opens in a new tab)About anthropics/claude-code
The SECRET Claude Code Upgrade That Has Everyone Going Nuts (Full Guide) (opens in a new tab)
The title names the project, the description links the project website.
Watch on YouTube (opens in a new tab)Independent creators. Listing a video implies no endorsement, sponsorship or partnership.
Sources
- Claude Opus 5.5 is INCREDIBLE at building video games (opens in a new tab)
First-person account · youtube.com · Published 4 Nov 2026 · Source checked 13 Nov 2026, 19:26 UTC
What this source supports
- Builds a Unity game with Claude Code on Opus 5.5 from a single published prompt
- Prompt scopes a third-person demon-slayer roguelike down to a first vertical slice of spawning enemies and sword combat
- Chapters cover the first slice, gameplay improvements, graphics, new assets and final tests