It had 200 achievement points that you could obtain in about 30 minutes. Once you completed it, you'd probably never go back. It only had local multiplayer, and it wasn't very different from the campaign.
For a free game, and for frustration free achievement points, it was fun. But they probably pulled it because of it being free, and it might have been a deal that Doritos had to cover the cost, and when they stopped Microsoft dropped it. I'm just speculating, but it makes sense. Microsoft doesn't like hosting free things to download, so usually a sponsorship has to cover the price somehow.
You'll probably have little luck getting a code from Doritos, as it didn't have a promotional code, so it wouldn't make sense for them to have one to spare.