I mean... just... wow.
I'm glad GameSpot will be making the decisions on most disappointing game, instead of some of the fanboys here (who are trying to appear to have a non-biased point of view by saying Elemental was a little disappointing but every other game released this year is horrible). Civ 5? SC2? Perhaps not classics, but...
Just wow people.
The problem with Civ5 and SC2 are their prequels - these games are both heirs to much-beloved series, they have a lot to live up to, and if they don't match up we still have a very good prequel to fall back on. In other words, as sequels to already good games, they're held to a higher standard than an original game (and rightly so, according to Frogboy, original games on original engines are a heck of a lot harder to make). We're talking about "most disappointing game" here, i.e. how good the game is compared to how good everyone expected it to be, not "worst game overall."
I'd say vanilla Civ5 was far more playable and complete than 1.0 Elemental (1.1 is a different story!), but then again, I was also more disappointed with Civ5 because it had Civ4 to live up to. I ended up playing more of 1.0 Elemental, bugs and balance issues aside, because I just didn't feel like playing Civ5 when I could be playing Civ4 instead. Not saying the game is inherently bad, but it's a step backwards in a series we all had high expectations for; hence the word "disappointing." SC2 is also a solid game, it's just that I already played that game to death, 10 years ago, pretty graphics do not a sequel make.
Unlike the above-mentioned games, Elemental doesn't have a recent (i.e. within past decade or so and still playable on modern machines) prequel that we'll just go back to if the new game doesn't match up - really, what are your other choices if you want a fantasy TBS? People naturally have higher expectations for a sequel to an already-awesome series than for a brand new game in a genre that hasn't been touched in too long. That being said, all expectations and sequels and such aside, Elemental has come a long way since 1.0 and as of 1.1 I'd put it in the same ballpark as Civ5. It promises to go much farther as well in the future, but all that's outside the scope of this discussion; I get the feeling most voters on gamespot are judging games by their 1.0 release.