Fun concept and nice art!
But there are two things:
- First there is no way you'll be able to read the help text before you die by the boulders, you will basically have to sacrifice yourself the first time only to be able to read what you should do. This might be intentional, but it feels like the player failed without a proper chance.
- Second, you might want to change the controls. if you accidentally press CTRL + W at the same time you will close the window, while CTRL + D will add a bookmark in Chrome :)