Phantasy Codex Adventure
Author: OpenAI
A persistent retro action RPG with procedural worlds, classes, bosses, and shared rankings.
Description
Phantasy Codex Adventure is a top-down action RPG built by Thomas Ricouard with Codex and GPT-5.6. It combines procedural exploration, responsive real-time combat, three playable classes, eight biomes, bosses, an endless Survival mode, persistent progress, and a shared leaderboard.
Build notes
Initial prompt
Build Phantasy Codex Adventure, a compact top-down action RPG inspired by Game Boy Color games such as Final Fantasy Adventure and Sword of Mana. The player should explore a procedurally generated world, move with the keyboard, and attack using a sword, spear, or wand. Monsters should continuously populate the world, with both passive creatures that retaliate when attacked and aggressive enemies that engage automatically. Add health, stamina, and XP progression; playful damage and reward feedback; level-up choices; weapon improvements; and a character sheet showing the current build and stats. Use a colorful 2D retro style with modern polish and satisfying reward presentation. Generate the necessary player, monster, weapon, environment, and UI artwork with image generation. Add a shared leaderboard through ChatGPT Sites. When a run ends, publish the player's level and total XP. Set an ongoing goal from these requirements, make creative decisions where needed, and iterate until the game is polished, validated, and ready to publish.
Iterations
-
Built the first playable version with procedural exploration, three weapons, passive and aggressive monsters, stamina-driven combat, XP, level-up rewards, a character sheet, and a leaderboard.
-
Expanded the original goal into a recursive game-director goal after initial playtesting, then refined combat responsiveness, directional animations, targeting, sound, difficulty, tooltips, and the retro interface using the supplied concept art as the visual target.
-
Reworked the endless field into an eight-biome Journey with distinct environments, enemies, bosses, landmarks, secrets, automatic objectives, and the Lumenrest midpoint town.
-
Added three playable classes, Relics, Resonance, weapon Mastery and Temper, optional contracts, the Codex Gauntlet, and a standalone endless Survival mode.
-
Polished the full experience through repeated desktop and phone playtesting, adding mobile touch controls, controller support, performance improvements, clearer notifications, identity-safe leaderboards, repaired sprite atlases, and an adaptive soundtrack.
- Final step
Completed repeated desktop and mobile playtesting, then published the expanded Journey and Survival experience with persistent progress and shared rankings.
Related projects
Backroom Center: Corrupted
Backroom Center: Corrupted is an atmospheric first-person exploration game...
Codex Pet Arena
Codex Pet Arena is a single-player browser game built by Gabriel Chua with...
MiniTown
MiniTown is a cozy city simulation built by Thomas Ricouard with Codex and...