I added the ability to record videos to this thing, and also the ability to specify when buttons should be pressed on a timeline, with a timeline preview, so as to specify what buttons should be pressed for each frame of the game and see what effect it will have. Here's some not-that-impressive Mario gameplay I made using that feature.

I also used that ability to see into the future to make this video where every shot hits an enemy.

The videos have a weird aspect ratio. Hopefully they play correctly. If not then you might try downloading them to your computer and playing them with something other than your web browser.