Codex Pet Arena

A fast, colorful platform arena where animated pets collect tokens and grow.

PlayableOpen source

Description

A single-player browser platformer where players choose one of eight unique pets to compete against CPU rivals in a scrolling arena. It features rotating maps with dynamic platforming, hazards, growth mechanics, and arcade-style combat effects like screen shake and particles.

Descriptions, tags, and model credits may be AI-generated or inferred from public sources and can be incomplete or wrong. Learn more.

Details

Why this is interesting: A high-quality demonstration of building complex game mechanics, logic, and assets through iterative AI-assisted…
Attributed to: @gabrielchua
Built with: Codex
Links: developers.openai.com
View tweet
View GitHub repo
Tags: #platformer #codex #react #browser-game

Discovered: X
First posted: X · Jul 12, 2026
Listed: Added 90d ago
Build: Strong
Models: Strong

Prompt

Build a playful single-player browser game called “Codex Pet Arena.” The player chooses one of eight original animated pets and competes against CPU-controlled pets in a large side-scrolling platform arena.

The main goal is to collect glowing Codex tokens placed across platforms, moving routes, hidden corners, and risky high places. Each token increases the pet’s score and gradually makes it bigger. Pets can bump or stomp one another, causing some tokens to spill out for anyone to collect. The biggest, highest-scoring pet should feel powerful and lead the leaderboard.

Start with a fun core: responsive movement and jumping, a scrolling arena, simple platforms, collectible tokens, and CPU pets that can move around and compete for them. Then add growth up to 3×, attacks, occasional power-ups, changing maps, and satisfying effects.

Use ImageGen and the hatch-pet skill to create eight original pets with distinct personalities and a small set of consistent animations.

Make the arena wide enough to explore in both directions. Add moving platforms, spring pads, shortcuts, hazards, and rewarding token routes. Change the map and rearrange the platforms every 30 seconds. Give different maps their own playful effects, including a Moon map with low gravity.

Keep the interface simple and let the game fill the screen. Add upbeat music, fun sound effects, particles, screen shake, and other small touches that make collecting tokens and hitting rivals feel satisfying.

Make it colorful, fast, slightly chaotic, and easy to understand within a few seconds. Focus on creating something genuinely fun and playable rather than reproducing every possible feature.

Source

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Games

Codex Pet Arena

A fast, colorful platform arena where animated pets collect tokens and grow.

byGabriel Chua

PlayableOpen source

Description

Descriptions, tags, and model credits may be AI-generated or inferred from public sources and can be incomplete or wrong. Learn more.

Details

Why this is interesting: A high-quality demonstration of building complex game mechanics, logic, and assets through iterative AI-assisted…
Attributed to: @gabrielchua
Built with: Codex
Links: developers.openai.com
View tweet
View GitHub repo
Tags: #platformer #codex #react #browser-game

Discovered: X
First posted: X · Jul 12, 2026
Listed: Added 90d ago
Build: Strong
Models: Strong

Prompt

Use ImageGen and the hatch-pet skill to create eight original pets with distinct personalities and a small set of consistent animations.

Make it colorful, fast, slightly chaotic, and easy to understand within a few seconds. Focus on creating something genuinely fun and playable rather than reproducing every possible feature.

Source

Codex Pet Arena

Description

How it grew

Codex Pet Arena

Description

How it grew