Way too buggy to submit.
The starting positions and velocities of the mines are seemingly random. This makes it extremely likely that you'll hit one before you have time to react. I would add a check to see if the mines are too close to the player's location before they start moving, or pause at the start and let the player see the velocities before they become unpaused.
If you click outside of the window you can't regain control unless the page is reloaded. Definitely fix that.