Hey, guys!

I read that games running on Java game engines could be embedded and browser playable, but upon uploading the .jar file it seems it just gives a dark box. It doesn't seem to be just my game either. Another entry that was working before (which can be found here https://sirpythagoras.itch.io/vaporbird) also results in the same thing. Just a slightly darker box, and you're forced to download the .jar file. 

Is it still possible to embed Java games in the browser?

Thanks in advance!