The single-player campaign, multiplayer, art, music, and content are not open source.

https://github.com/nkzw-tech/athena-crisis

So cool though.

This is incredible.

Athena Crisis is an example of how to build a high-quality video game using only JavaScript, React, and CSS. By open-sourcing Athena Crisis, we are following through on our commitment to open source our core technology and help push the Web forward as a game development platform.

I absolutely love browser-based gaming. But there’s not a lot of resources to learn how to build anything advanced beyond the casual games. After a while, every browser game migrates to a “real” game engine. Which makes sense. But doesn’t help push web games.