Epic’s AI MegaJam opens to browser games built with Unreal 5.9

Epic Games opened its AI MegaJam at midnight Eastern Standard Time on November 12 with an option to submit a game that runs in a browser. The experimental web target comes from the Unreal Engine 5.9 preview, which Epic released on November 9. A team can use it to give judges a playable web build that needs no separate game installation.

Teams entering with Unreal Engine can still submit packaged desktop or mobile games. For the browser route, Epic’s submission page calls for a shipping build from the 5.9 MegaJam Preview. The game goes on itch.io, with a limit of under 500 MB for the whole web build and under 200 MB for any one file.

The browser runs the game code

A web build runs game code on the player’s device through WebAssembly and draws the scene with WebGPU. The developer needs a C++ project to make the web build. Epic’s Preview 1 issue list says that the precompiled Mac and Linux versions are missing some web support files. For those systems it directs developers to build the engine from source.

The default web graphics path uses Unreal’s mobile renderer, with separate tiers for desktop browsers and phones. Epic says Chrome offers the best experience in the preview and warns that preparing a game for the web can take longer and that performance issues can still occur. The company also lists a bug that can break the picture or touch controls if a phone is rotated while the game loads. Epic plans to rework parts of the web renderer before the full 5.9 release.

Coding agents can work inside the editor

The preview also brings coding agents into an assistant panel in Unreal Editor. They connect through Unreal MCP, a system for exposing editor actions to compatible tools. Version 5.8 introduced the experimental connection. In 5.9, it starts with the editor and exposes more kinds of work, including level creation and gameplay testing. A developer can ask a connected agent to inspect the scene or move an object through the tools available in the editor.

What the agent can change depends on the tools available in the project. Epic lists an issue in the first preview in which a new project starts the connection with some of the tools for editing levels and assets turned off. An agent can be connected and still lack an action for moving an object in the scene. The connection accepts requests from the computer running the editor by default, according to Epic’s documentation.

A separate experimental feature, Unreal Canvas, can use an image captured from a project as a reference for generating new content. A developer can frame a scene in the editor and carry that composition into an image or a 3D asset experiment. Epic lists an Nvidia GPU with at least 8 GB of video memory for local processing such as segmenting objects or estimating depth. Connected outside providers bill generation through the developer’s own account.

Epic says it built the MegaJam preview in about a week. Agents helped bring AI tools over from the Unreal Engine 6 development branch and wrote the web platform code, starting with the retired HTML5 support in Unreal Engine 4. Engineers directed, reviewed and tested the work. Epic says the build received a shorter quality-assurance pass than its usual preview.

The jam accepts solo entrants and teams of up to five. A team chooses either Unreal Engine or Unreal Editor for Fortnite. Entries made with the Fortnite editor use a fixed private version code for the island. Both tracks require a 30-to-60-second gameplay video, and use of AI is optional. Submissions close on November 15 at 8:59 p.m. Eastern Standard Time.