I don't get your last point, Yahtzee. Complaining about games being a time sink is complaining about the whole modern gaming industry. The last time i had some challenge was when i was playing Contra (or Atari2600 games, since the games were about high score, so it had a way to compare yourself with others, a very multiplayer style of gaming), with a fiew exeptions, ofcourse, but unless you're an old PC gamer, you haven't heard of those. Gaming right now is exactly like watching Avatar and is praised by the same kind of people. I sat through it, it was pretty and i didn't feel completely like i'm just aging watching it so i guess i can't really ask for my money back. That's about as good as it gets nowdays.
The only challenge in gaming right now (mostly because any new game is a tired and old concept that old gamers blitz though) is multiplayer, and you're not going to be talking about that ever, since it's almost impossible to review. It's mostly noticable when any MMO talk comes down to what the client is capable of. The kind of thing that's mostly irrelevant when it comes to MMOs. You'd propobly only look at the same aspects of UT3 or SC2.