In 2008, Doritos released Dash of Destruction, the winning entry in an "Unlock Xbox" call for advergames. It was nice for Mike Borland, who pitched the winning concept, but the shoddily-developed title really only served gamers as being one of the easiest titles ever released to secure all of the Achievements.

So when Doritos' Snackstrong Productions announced the "Unlock Xbox" competition would return in 2010, it is understandable that many gamers probably just skimmed the news and moved on without giving it second thought. But Doritos' decision to release the two finalists on Xbox Live Arcade, totally free of charge, allowing fans to vote for the winner, shows that the concept has come along way, even if it is still just an advertising effort for the chip company.

Doritos Crash Course was declared the winner of the competition at the end of last year, but gamers would do well to download both Crash Course and Harms Way - By Doritos, because both are fantastic efforts that are worth well more than the price of free at which they've been made available.

Doritos Crash Course plays like something that could have been a first-party effort from Microsoft for XBLA. Gamers get to take control of their Xbox avatars and play through a series of obstacle courses that remind of American Gladiators...without all of the overly muscular beat-downs.

The controls are kept simple - basically analog to run to the right, climb and slide; and "A" to jump - while the courses grow increasingly ridiculous and complex. The levels are well-designed, albeit not aesthetically varied and without inherent replay value.

But fans will likely keep coming back thanks to the Trials HD-like leaderboards that will have friends competing for the top spots. And with the game released for free, it's likely that many friends will be helping to stoke the competition on those boards. With fun presentation and simple controls, Crash Course is both accessible and fun.

Harms Way may not be quite as polished, but the concept is solid. Players work in teams. On the ground, racers are stepping on the gas and violently trying to stay ahead of the competition to be the first to go three laps and cross the finish line. Sounds fairly basic.

But teammates man and switch between sniper turrets scattered high above the tracks. It is their goal to help their racers beat out the competition. The one obvious way to do this is to directly lay waste to the opposing racers by targeting the vehicles on the course.

Snipers can also affect the race indirectly, too. They have the opportunity to shoot open shortcuts for their racers, or drop environmental hazards on the competition. Of course, doing these things wrong can also backfire.

Harms Way offers a campaign mode, but it is the variety of multiplayer options that will grab hold of fans. Offline, two-player co-op, or one- to four-player multiplayer is available. Online multiplayer is up to eight players, also with a co-op option.

Again, Harms Way is not completely polished, and its graphics could use some work, but for free, it is well worth the download and time. The separation of the battle and racing elements adds strategy and teamwork to the mix, and is a truly unique concept in the Xbox Live Arcade realm.

The "Unlock Xbox" contest has taken a big turn for the better this year. Sure, it's another major advertising campaign on Xbox Live, but the net gain for gamers, for the price of seeing the Doritos logo a few times, is two great XBLA games at no cost. And they are both great to play with friends. And if Doritos is going to churn out titles this solid in the future, here's to the competition returning in 2011.