I don’t want it to have any JavaScript
That’s not going to happen. I also don’t understand why you wouldn’t want JavaScript. All the concerns with it are about the times when you access a website by a proprietary software maker and encounter obfuscated and opaque code that you can only with great difficulty reconstruct what it does. But JavaScript “in the right hands”, like on a FOSS website, is perfectly fine and even required to make a webpage that can actually do something more than simply display text or images.
Games made in Unity or Unreal Engine literally do not require any additional effort from the developer aside from choosing Linux as the build target from a drop-down menu. So native Linux ports of UE and Unity games cost virtually nothing.