By almost all accounts, Aliens: Colonial Marines isn't a good game. Patricia certainly didn't care for it, saying that "it was literally a pain just to get through."

But hey, it happens. Sometimes, for various reasons, video games aren't as good as the people who made them wanted them to be. What's remarkable with Aliens: Colonial Marines has been the fact that the game's developer, Gearbox, showed A:CM off in numerous hands-off demos and previews, and those demos looked far better than the finished game.

In the video above, two chaps from VideoGamer.com put the demo footage side by side with the actual game. The results are… pretty galling, actually. (They've got the "Demo" and "Final" labels mixed up for a chunk of the video, but have remedied it using YouTube annotations.) Update: They've now posted a new video with the correct notation; that's embedded.

They're playing on PC with their settings maxed, and you can see how vastly different huge chunks of the game look—the final version is missing detail, environmental effects, dynamic lighting, even whole characters. They also take a look at the Xbox version toward the end.

In this video from last year, Gearbox president Randy Pitchford walks viewers through a demo presentation of the game. Patricia, who has played through the game, tells me that the final game is very different from this demo.

It's hard not to get the sense that the story behind Colonial Marines' development is more tortured than your average game. Watching these videos, it seems like Gearbox did know how to make a good Aliens game, but that somewhere along the way, they had to compromise the game.

I've reached out to Gearbox to get their perspective on why the demo differed so vastly from the finished product, and will update if I hear back. In the meantime, this is a good reminder that no matter what a game looks like before it comes out, it's always wise to take these sorts of hands-off demos with a grain of salt. Or a bucketful.