I found Portal to be lacking. Not because it's too short, as it's often accused of being; rather, because quite frankly, the gameplay was lackluster and repetitive. It was sort of cool and novel at the beginning, but I grew tired of shooting blue and orange rifts into the same gray walls sometime around test chamber 10. Playing with a mouse and keyboard was one of the worst control schemes I've ever dealt with, alongside the likes of Super Metroid. The music was nearly nonexistent (I'll admit that "Still Alive" was excellent). The writing was good, but I'm more likely to play a game with questionable writing and good gameplay (Kingdom Hearts, Metroid: Other M) than one with good writing and questionable gameplay (Portal, The Legend of Zelda: Ocarina of Time). It is not the finest single video game ever created by mankind, and the point certainly isn't unarguable.
And as such, it's overpriced. It's a good thing I got it for free, because I would have been royally ripped off had I not.
"Literally insane"? Have I ever told you about that pet peeve I have about people misusing the word "literally"?