Please be as specific as possible when letting us know what is missing or incorrect. For example, say "this game's trophy difficulty should be 8/10", with a link to a website corroborating this difficulty estimate (if possible), not "this game's trophy difficulty is wrong".
What is Art? Sure, it's paintings and sculptures and things like that. But really… what is Art? Well, rather than dip into that profound can of worms, we've summarised our answer with a lovely collection of items.