It's a neat idea, but whenever I stopped time, I ended up dying before time resumed, since I can't move out of the way of bullets that spawn while time is still stopped. As such, it's actually safer to never stop time. Still pretty neat, though.
By the way, I'd strongly recommend adding a thumbnail image for the game page. Per the rules, you don't have to count making your game page as part of your 3 hours, so it's fine to do it afterward.