This being the last day of the year, and the last weekend of your holiday vacation, it's a great time to spend those Microsoft Points you received as gifts, or to treat yourself to something fun with which to usher in the new year. Here are my recommendations of games released to Xbox Live in 2010 that aren't to be missed.

Limbo: This platform-puzzle game is perhaps most memorable for its morose atmosphere and the macabre results of failure. With almost no backstory, a boy sets out on an adventure through a woods devoid of color or background music. His weapons with which to defend himself from giant spiders and worse are limited to the player's ability to make him jump, climb, push, and think. At $15, the game is pricey for a digital title, but it's 33% off today only — either way, a fair price for what Wired called one of the best games of 2010.

Limbo - Treacherous World Gameplay | HD

Cthulhu Saves the World: You may not have heard of indie developer Zeboyd Games, but their previous Xbox Live release, Breath of Death VII, sold 30,000 copies. Created by a long-time gamer and RPG aficionado, the game capitalized on the rich history and tradition of 8-bit RPGs while correcting many frustrating aspects of the genre, such as random encounters. Cthulhu Saves the World is its spiritual successor, with more inside jokes and great gameplay but with a presentation that's been bumped up to 16 bits and a story that will take ten hours to experience, unlocking multiple replay modes. The price tag on this game is triple that of its predecessor and will set you back a whopping $3.

Cthulhu Saves the World official music video.m4v

Pac-Man Championship Edition DX: Despite the name, Pac-Man CE DX is so much more than a remix of the 2007 Championship Edition. With "ghost trains" that harken back to the old computer game Snake, a bullet-time effect when Pac-Man is cornered, a variety of skins by which to customize the game's look, and more gameplay modes than you can shake a power pellet at, it's an impressive amount of content and replay value for $10. As the creator of Cthulhu Saves the World wrote:

Pac-Man: Championship Edition DX is a worthy sequel to some of the best games ever created (the original Pac-Man and Pac-Man: Championship Edition) and is probably the best game that will come out this year. Given that this is a year that has included gems like Super Meat Boy & Civilization V, that’s saying a lot.

PAC-MAN Championship Edition DX trailer from Namco Bandai Games

Return All Robots!: RAR! is a top-down puzzle game in the tradition of the Adventures of Lolo. Players direct a scientist whose remote control will send good robots back to base while avoiding their evil counterparts. Check out our preview for more details and a gameplay video. Again, you'll be supporting an indie developer and getting a great title for a mere $3.

Return All Robots! Launch Trailer

Chime: Released in early 2010, this top-down puzzle game invites you to place blocks anywhere on a playing field such that they form perfect rectangles. As with Lumines, a line regularly sweeps the playing field, clearing any completed pieces. An excellent soundtrack, including a piece by renowned composer Philip Glass, is enhanced by sound effects made when the line encounters your shapes. Play until you've completed the level, or in time trials of 3, 6, or 9 minutes, for only $5.

RISK Factions: The classic board game comes to Xbox 360 with multiple enhancements and features. Though the classic map and rules are available, other modes offer rewards for capturing specific terrain; multiple factions (all identical in gameplay); battle animations; online play; and more. This game has been on sale for 50% off all week; today is the last chance to get it for only $5. Check out the reference to an Apple II contemporary in this cutscene:

Risk: Factions - Introduction Chapter 3: Animatic

Worms 2: Armageddon: You'd never guess how much fun it could be to arm a nematode with a bazooka and send him to kill his brethren until you've tried it. This turn-based, 2D strategy game pits teams of worms against each other, using bizarre terrain (a construction site, a moon made of cheese) and armaments (banana bombs and exploding sheep). This $10 iteration in the 15-year-old franchise is already a few years old, but a $5 battle pack released in the summer of 2010 adds new levels, weapons, and more.

Worms 2: Armageddon - Debut Trailer [HD]

Portal: Still Alive: Valve's release of Portal 2 for Xbox 360, PS3, Mac, and PC has been continuously delayed and is currently slated for April 18, 2011. While waiting for this full-fledged retail game, you'll find it's not too late to crawl out from under your rock and discover what all the fuss is about. Portal came out in 2007 as part of a compilation of games, but an enhanced version of this first-person puzzle game was released as a standalone product for Xbox Live in 2008. Although not a 2010 release, it's the only Portal product available this year — and at $15, it's the cheapest Portal experience you'll find in 2011, too.

Portal Teaser Trailer

With so many games available for the Xbox 360, this list can only begin to scratch the surface. What were your favorites this year?