Developer Builds Real-Time 3D Pokémon Battle Game with Claude Code in One Week

Pokémon fans have taken their creative ideas to a new level. A developer shared their project PokeBrawl on Reddit—a real-time 3D Pokémon battle game, with a free demo and open-source code. What's even more surprising is that the project took only one week, completed entirely with the assistance of Claude Code. For those skeptical of AI programming capabilities, this case is worth a closer look.

Turning Turn-Based into Real-Time Battles

The biggest change in PokeBrawl is the battle logic. Traditional Pokémon is turn-based—players select commands and wait for resolution; PokeBrawl lets players directly control Pokémon movement and dodge attacks, with four skills each having cooldown times, requiring players to judge release timing while fighting. Opponents can be AI or 1v1 online matches with friends.

This design means combat shifts from "strategy queuing" to a hybrid of "action + strategy." The cooldown mechanic forces players to trade off between attacking and saving skills, while movement and dodging introduce a spatial dimension—things not present in official Pokémon titles. According to the developer, the multiplayer portion is implemented based on ENet, using the Godot 4.7 engine.

ENet is a lightweight reliable UDP networking library that provides connection management, packet ordering, and retransmission mechanisms, commonly used in latency-sensitive game multiplayer scenarios. Compared to TCP, ENet provides reliability on top of UDP on demand, avoiding TCP's head-of-line blocking issues, making it suitable for real-time battles requiring low-latency synchronization. Godot 4.7 is version 4.x of the open-source game engine Godot, featuring built-in 3D rendering, physics, and scene systems, supporting GDScript and C#, and is often chosen by indie developers for being lightweight and free. Godot 4.x has significantly rewritten the 3D rendering pipeline and performance compared to 3.x.

The Key to Finishing in One Week: Test-Driven + Real Data

Building a playable demo in one week wasn't about letting AI write blindly. The developer summarized two approaches that made it "work."

The first is built-in tests for every mechanic. The project has about 25 tests, plus automated AI-vs-AI matches, so any change that breaks existing functionality is immediately exposed. This is essentially a safety net for AI-generated code—Claude Code can quickly produce implementations, but only tests can ensure it hasn't quietly broken something else.

The second is data from real projects. Attributes, move learning tables, and move and ability behavior logic all come from Pokémon Showdown and Cobblemon data. This way Claude implements real rules rather than making up its own. Currently the project has implemented 79 moves and 22 abilities. This detail is worth noting: the ceiling of AI programming largely depends on the quality of context you feed it.

Test-Driven Development (TDD) is a development method where you write tests first, then implementation code. The developer first defined expected behavior for each mechanic and wrote automated tests, then had Claude Code generate implementations and run tests to verify. This approach is especially effective for AI-assisted programming: AI-generated code may have hidden defects, and a test suite can quickly regression-verify after each change. In PokeBrawl, about 25 tests plus automated AI-vs-AI matches essentially build a continuous verification feedback loop, keeping AI output always verifiable rather than a one-time generation that can't be maintained.

Pokémon Showdown is an open-source Pokémon battle simulator implemented in JavaScript/TypeScript. Its codebase contains complete type effectiveness tables, move data, ability behavior logic, and learning tables, organized as structured data that's easy for programs to read. Cobblemon is a Pokémon mod based on Minecraft that also maintains a set of open-source game data and 3D model assets. Both are authoritative data sources maintained long-term by the community. By directly referencing them, the developer essentially outsourced "rule correctness" to existing data validated through extensive battles, leaving AI only responsible for implementing logic without inventing values from scratch.

Open Source and Asset Copyright Handling

PokeBrawl's code is open-sourced on GitHub, with a Windows demo available for direct download. Regarding assets, the developer made clear copyright attributions: Pokémon models, animations, effects, sound effects, and battle UI come from the Cobblemon team (CC BY-NC 3.0, authorized); music uses Pokémon arrangements by The Noble Demon with attribution; trainer artwork comes from Pokémon games via Pokémon Showdown; move and ability data comes from Pokémon Showdown and Cobblemon. The project is positioned as a non-profit fan work, unaffiliated with Nintendo, Creatures, GAME FREAK, and The Pokémon Company.

For those wanting to make games with AI, this project's reference value isn't in the "one week" speed, but in demonstrating a reusable methodology: use existing data sources to ensure rule correctness, use tests to ensure change safety, and position AI as an "implementer" rather than a "decision-maker."

Frequently Asked Questions

Is PokeBrawl free? Yes, the demo is free to download, the code is open source, and it's a non-profit fan project.

What platforms are supported? Currently a Windows demo is available, using the Godot 4.7 engine.

How does multiplayer work? It supports 1v1 online battles via ENet, and you can also battle against AI.

How much AI was used? The developer completed development with Claude Code assistance; specific division of work wasn't detailed.

One-line Summary

Developer builds real-time 3D Pokémon battle demo and open-sources it with Claude Code in one week.

Paragraph Summary

A developer completed the PokeBrawl real-time 3D Pokémon battle game demo in about a week using Claude Code, free to download with open-source code. The project changes traditional turn-based combat to real-time action battles: players directly control Pokémon movement and dodging, four skills each with cooldowns, supporting AI battles and ENet-based 1v1 multiplayer on the Godot 4.7 engine. The key to finishing in a week lies in two things: configuring about 25 built-in tests per mechanic plus automated AI-vs-AI matches to ensure AI changes don't break existing functionality; and sourcing attribute, move, and ability data from real projects like Pokémon Showdown and Cobblemon, letting AI implement real rules rather than making things up. Assets are clearly attributed under CC BY-NC 3.0 and other licenses, as a non-profit fan work unaffiliated with Nintendo and other official entities.