There are two ways to fail at Exploding dots: 1. The dots multiply to the point where they fill up the whole screen. It's a slow ugly death and it proves you weren't doing your job. 2. You accidentally click the purple background instead of a dot. This is quick and painless death but at least you went out trying to win. Either way though, you lose and will be haunted by your own failure, especially as you look upon the leaderboard and see that it populated by people with better attention to detail and more determination than you could muster.