Chase bosses, where they run off, and you have to dodge a load of shit to get close enough to hit them. Usually all it takes is one wrong move, and you lose all your progress getting closer and the boss goes to maximum distance whether you were still ages away, or a couple of inches.
Worst one of those I ever fought was in Sonic Generations (a game where four out of seven bosses are actively fleeing from you). The last boss has you doing the usual Super sonic thing of "lol I'm invincible, but if I hit anything I get knocked back, and I need to keep my rings up or I die for some reason". The only way to even try to get close to the boss is to boost constantly, so you're dodging stuff that will appear half a second before you can react to it. Furthermore the boss itself has an attack where it teleports it's arms to you that can leave them right infront of it's one weak point.
But all of that is nothing compared to it's final trick. It arbitrarily, and randomly switches between the two perspectives, side on, and infront. Everytime it does you have to swap as well, a move which losses all the distance you had gained, and can stop you from grabbing any rings. The only hint you get that it's switching is a character announcing it, as it's doing it, so you've no way of knowing if you're getting close enough to win, or if you're wasting time.
