Try it live Description
ECHO PROTOCOL is a 3D time-loop action puzzle. A floating clockwork city has forgotten its dawn, and your teammates are your own recorded actions. It is a gift for players who think they must face every challenge alone: one player can be an entire squad.
Record your movement, shots and dashes on an 18-second timeline. Rewind, and an echo repeats that exact path and firing pattern, then holds its endpoint. Cooperate with up to three past selves to synchronize relay plates. Captured relays and city memories survive every rewind.
Five districts develop the idea: paired plates in the Silent Garden, furnace hazards in the Lost Foundry, three simultaneous actors in the Memory Archive, four actors linking both relays of the Mirror Observatory, and a three-phase battle with the Warden at the Dawn Spire. Along the way you choose permanent upgrades, build combat chains and activate resonance. Fifteen optional memories reveal the voices of the city, and local checkpoints support return visits.
The district landmarks, architectural components, enemies, the civic airship and the lamplighter are Tripo models. Original code adds floating foundations, ceramic mosaics, working machinery, trams, city lights that wake as relays are restored, holographic echoes, the interface, combat effects and synthesized music. The game supports keyboard and touch controls, a Chinese/English interface and adaptive graphics, and includes a gallery of the actual in-game models.
No earlier version of the game existed before the hackathon. The project code, replay system, five-district campaign, interface, procedural scenery and synthesized audio were built from scratch starting October 3, 2026, with Codex assistance, and all 24 Tripo models were generated during the event. No external music, voices or stock art were used; Three.js and meshoptimizer are credited MIT-licensed libraries.
How Tripo was used
Tripo is the visual foundation of the playable city: all 24 original models in it come from Tripo.
- 24 models: five core models, five district landmarks, nine architectural components, three enemies, a civic airship and a lamplighter, including the hero and the Warden.
- One coherent style: the five core models were generated from text prompts; the other 19 were made with Tripo H3.1 image-to-3D from original reference images the author created with OpenAI image_gen, unified in ivory ceramic, oxidized bronze and jade glass so they form one coherent 3D city.
- Retopology and rigging: the hero and the relay were retopologized with Tripo Smart Mesh, and a 65-joint rig downloaded from Tripo drives the hero and every independent echo; the idle, run, dash and fire skeletal actions were authored in the author's own code.
- Ready for the browser: meshoptimizer simplification, resized textures and instanced scenery make the whole model set playable in a browser.
