I tried running the demo with Learn To Fly (the penguin flying/distance game); the physics in the game is a bit broken (slowly rising off the ground) and there is no controller input.

But overall a really cool project; i'm not bashing it ofc, it just needs some more work but it seems pretty capable in other games.

Future Edit: After spending too much time trying to install the addon for firefox from their site (as i don't like the idea of only installing validated addons) I was able to go into about:config and change "xpinstall.signatures.required" to false. Leaving this here if anyone else runs into this problem.