It may not have been the smoothest year for the Xbox One, but that doesn't mean it's not worth celebrating. Microsoft's newest console did have a bit of a slow start, thanks to strange policy changes and pricing stumbles, but once the library began to grow and the Kinect camera became optional, the Xbox One really started to take off. Now, one year later, Microsoft has plenty to celebrate.

To finish off the year in style, Microsoft announced a litany of different giveaways and promotions. Free downloads and movie rentals are great, but the biggest draw of the Xbox One's birthday celebration is that Microsoft is offering up its open-world chaos simulator Sunset Overdrive for free...for 24 hours.

Considering it's one of the bigger exclusives Microsoft has this holiday season (nothing can really touch Halo at this point), it makes sense that the publisher is only giving players a taste of Sunset Overdrive. Even so, it's relatively unheard of: an unrestricted demo for an open-world game (including the full multiplayer suite) isn't something that happens everyday in the first place, but the game only came out a month ago at that. That being said, it is an unrestricted demo, meaning that the full 20+ Gb download is required to play.

If you're not looking forward to Sunset Overdrive (or already own it), Microsoft is offering up plenty of other goodies for early adopters as well. If your console was purchased before Oct. 1 of this year, you're eligible to download:

 - A Year One Gamer Picture
- New Xbox One backgrounds: A special Year One background as well as an exclusive Day One background for those who unlocked the Day One achievement
- A Year One background image
- A free rental of "Halo 4: Forward Unto Dawn" (for a limited time)
- A free rental of "Dragon Ball Z: Battle of the Gods" movie

There's also a big sweepstakes, so again - if you purchased your console before Oct. 1, you're entered to win:

  - Xbox One Limited Edition Call of Duty: Advanced Warfare Bundle
- Xbox One Special Edition Sunset Overdrive Bundle
- One month membership for Xbox One-exclusive EA Access service
- Tiger Shark cash card for Grand Theft Auto V
- Forza gift pack
- Forza Horizon 2 Limited Edition Casio G-Shock Sports Watch
- Grand Theft Auto V gift pack
- Xbox Live Gold 12-month membership digital code
- Killer Instinct Season 1 Combo Breaker Pack
- Special edition Nissan 370Z, featuring a Casio livery for Forza Horizon 2
- Air Vehicle shortcut for Battlefield 4 for immediate access to all unlocks
- Arno's French Rapier for Assassin's Creed Unity
- 75 Platinum in Warframe
- Plants vs. Zombies: Garden Warfare Costume Pack for Peggle 2
- Epic Quest Table in Pinball FX2
- Dance Central Spotlight (full game token)
- Project Spark Premium - 15 days

It's a little strange that Microsoft would offer up an Xbox One for all those who already purchased the console...there's never too much of a good thing, right?

For all the details on the contest and unlockable items, check out Microsoft's official blog.