Introduce a big piece of sh*t like this:
Yes, this is the Pain Killer, end of chapter 2 boss. He looks visually impressive, but it's so tedious trying to kill him. The whole game is a morish fest of speedy quick despatching of huge hordes of enemies. Sometimes I don't even know how it runs, but it does. And then you get to the end of level bosses, which are very impressive. This one, however, is just darn right frustrating and annoying, and the balance is totally wrong. I can breeze through the whole game, but the step up in difficulty in killing this prick is 1000%. Not to mention the fact that you have to spend half an hour trying to work out how to do it, seeing as it's not just a case of shooting him.
Fair enough, I hear you say. It's supposed to be a challenge and variety is good right. Well, this is true, but the step up from killing people to having to puzzle solve, dodge his annoying arm thing which always comes up behind you, plus wait forever until he stands on a bubble just so that you can blow it up and wound him a bit ... it's just too much. This is a tedious bad guy, and now the only way I can be arsed to move on is to go and get an invincibility cheat or something, because it's simply too dull to try and kill him anymore.
Anyway, that's my rant about a good game, with a big pile of crap in the middle of it.