June 14, 2017 The WebGL version should be less buggy now. The mobile version has been updated as well. You can now create and select custom grabs.
If you're on a Mac and using a PS3 controller (10.6 and up) just plug it in, press the middle button and you'll be able to play automatically. If you're using a wired Xbox controller you'll need to download the tattebogle driver right HERE.
Note that if you're using an xbox controller you need an actual wired one. The power cord won't work unfortunately.