I'm curious what you guys have to say about this. Are there any games you consider perfect? Can a game even be perfect?
My example of a perfect game is always Portal 1. Portal 2 has more going on, but in 1 there just isn't anything to shave off. From start to end, there is nothing I'd change about the game. It's short, infinitely replayable, great pacing. I like Portal 2 a lot in concept, in concept it should be a perfect sequel, but it just doesn't keep the extreme tightness of the original game.
The real shame is all they needed to do, in my opinion, was balance the game around one different setting - making clumping optional, the way magic boxing worked. Click between, they clump, click adjacent, they stay pretty much in formation. You can literally go into the map editor and change this with some kind of checkbox, apparently.