Interesting concept, well executed. Great work! You should write explicitly to use WASD/arrow keys to turn left and right. They are not on the page in the section Controls. They are not in the game itself.
At the beginning I was just clicking on the display and thinking the controls may be broken...Some players may just abandon the game.
It would be nice to display what depth was reached at the end of the run.
Thank you. Good luck!