I had a similar problem with the in-browser emulator I just put on my page, where the spacebar would scroll the page. Here’s how I fixed it for spacebar:
window.onkeydown = function(e) { if (e.keyCode == 32 && e.target == document.body) { e.preventDefault(); } };
If your game isn’t javascript and is just embedded in the page, this will be an easy fix. If it’s javascript, I think it would have to count as part of the submission =/