It is an executable JAR file. I have tried building as an HTML5 project, but all the UI elements are scaled wrong and the framerate is terrible. I don't think I have time at this point to troubleshoot all of the bugs with the HTML5 build. I was hoping to have it be playable in browser, as it seems like more people would try it that way but it looks like I'll have to settle for a downloadable instead. Thank you both for the suggestions.