If you have any doubt that computer games are a valid and potentially serious art form, try playing Jason Rohrer's little gem, Passage. It's free and it takes mere seconds to download, and only a few minutes to play all the way through.
Though I guarantee you'll play it at least a second time.
Joel Johnson at bOING bOING Stuff says:
Where most games tell a story, Passage is just a sentence. But what a pregnant, forlorn sentence.
From start to finish, the game can be completed in five minutes. But there's no rush.
At Play This Thing the99th calls it “The Game That Almost Made Me Cry,” saying:
I'm talking about 8-color pixel sprites making me feel something that Final Fantasy could only pull off non-interactively with cheap (read: extremely expensive) parlor tricks of CG and professional voice acting.
Anthony Burch has a long review worth your time as well.
Mr Rohrer provides a creator's statement which is worth checking out, but don't make reading it a substitute for playing the game. He starts it by saying:
Your interpretation of the game is more important than my intentions. Please play the game before you read this.