I'm not sure there is anything I can do about the browser lag, unfortunately. Dragon ruby seems to not like rendering this many sprites on browser if you have a lower end system or a browser that caps framerate/memory use. I have no control over the loops, the game code is just updating a bunch of hashes and ruby values then passing it all to dragonruby to render.
The download one plays full speed for what it's worth. I hope you can try that!