The GhostWriter, a JavaScript 2D Game with Canvas
codepen.io
codepen.io
EDIT: well there you go : Uncaught TypeError: Cannot read property 'toLowerCase' of undefined
EDIT2: a relevant bug[1] and it even suggests a work around.
[1]:http://bugs.jquery.com/ticket/15220
chrome apparently does not have event.key ; you could try event.keyCode or event.keyIdentifier
A major issue is that codepen doesn't automatically focus the frame of the game, and this causes the keyboard event to be missed.