Really good concept, done entirely in HTML 5 from scratch, so thumbs up for that ! Clarity of it could be better though. We don't know there is a limit on the number of burger we can take before seeing customer (even though it's logic when you think about it). Control should be mention on the UI, didn't know I could move with arrow key.
The music is very well done and match the frantic nature of the concept. No sfx, unfortunately so cannot judge that. Good proof of concept I will say. Good Job Overall !