Update (24 Sep 2017)
I've added a pause button, and as was suggested by commenters @Felice and @apLundell I switched to using the pico glyphs for the graphics... it's a little less flashy looking overall, but gives a much nicer more consistent feel.
I've tried to keep it as simple for other game-makers to use as possible. As such it should work out of the box with html/js files that are exported from pico-8. All you should have to do to use it with your own game is drop the js, css and png files into the same directory as the html file and then link the files as described in the Readme on github:
Heres the code:
and a demo:
(go there on your phone, or resize your browser window to see the controls.)
and you can also see it in action on my game here: http://codyloyd.com/jazzyjeff/
I'd love any feedback or tips that you might have. I don't have a huge array of devices to test it out on, so if you find something not working let me know!