U.S. Xbox 360 owners who shell out the 5600 Microsoft Points necessary to net them Splosion Man, Marvel Vs. Capcom 2, Turtles in Time Re-shelled, Trials HD, and Shadow Complex between now and August 31st will get an extra 800 Microsoft points added to their account, basically cancelling out the price of Splosion Man. From a monetary standpoint, it amounts to getting $80 worth of Microsoft points for $70, which is a pretty good deal no matter how you look at it. Of course, if you don't buy all five games you get nothing, but that's the price you pay for not paying the price for everything.

Microsoft's annual Summer of Arcade promotion begins today, a five-week event designed to draw attention to new top-flight Xbox Live Arcade games, such as Splosion Man and Shadow Complex. We don't yet know how good these games will be — though we have high hopes. What we do know is that they, as is the trend with XBLA games, will contribute to the rising price tag of games on Microsoft's downloadable service.

Kotaku's Andrew Freedman and I pulled launch prices for the more than 200 Xbox Live Arcade games released since the 360's launch. At the top of this post, you'll see a chart that shows how the average price for downloadable XBLA games on the system has risen steadily in the past 46 months. (Note: The Xbox.com online marketplace lists the launch games for the 360 as being released in October of 2005 even though the system debuted in North America in November. For consistency's sake, we've started our chart at October of that year.)

The average price of an XBLA game in the 360's first month was just under 600 points at about $7.31. That has risen to more than 700 points as of last week, or $9.05. And that's not counting how the average will likely rise again during the Summer of Arcade. Four of the five games offered for the new promotion will run 1200 points.

The second chart Andrew and I made shows which prices have been popular, and which are going out of style. The days of games released for 400 points ($5) are nearly over. The 1200-point price ($15) is increasingly common.

Click graph to enlarge

The size of games offered through XBLA has increased over the years. Several top-quality titles, including Geometry Wars, Braid and Battlefield: 1943 have garnered acclaim.

But if you thought that XBLA was becoming a more expensive service, you're not imagining things.

You'll be playing Twisted Pixel's swell-looking Splosion Man much earlier than previously planned, on July 22nd, according to the updated schedule from Xbox Live's Major Nelson.

Later, on August 5th, you'll get access to Teenage Mutant Ninja Turtles: Turtles In Time Re-shelled on XBLA. Not a bad trade-off. If only we could do something about those prices, though...

Out of the games released, Castle Crashers is being heralded as a stand-out title for all of XBLA, while Braid wound up as the highest-rating XBLA title of all time, with Geometry Wars: Retro Evolved 2 and Bionic Commando: Rearmed also making the top 10. That leaves poor Galaga Legions. There there, little retro redux. We still love you...just not as much. Hit the jump for the full text of the press alert!

The Numbers are in: August was a Scorcher for Xbox LIVE Arcade

Sure, we are coming off a long, hot summer, but it was Xbox LIVE Arcade that really made things sizzle. Critics agree: With the season’s best games released over the span of five weeks, the Summer of Arcade brought new players to the Xbox LIVE Arcade service in record pace. “Castle Crashers” “Geometry Wars: Retro Evolved 2,” “Bionic Commando: Rearmed,” “Galaga Legions,” and “Braid” delighted gamers of all pedigrees and drove the most successful season on record for the downloadable games service.

Over the course of the five-week Summer of Arcade program there was a 58 percent increase in unique members purchasing titles, and August broke the monthly revenue high by 67 percent. August was also the first time that an Xbox LIVE Arcade game landed in the top 3 most-viewed pages on Xbox.com. The reason for all of this success? The games were really good.

“Castle Crashers,” an adventure title that came to the service on Aug. 27, currently sits at the No. 1 spot for the Top 10 Xbox LIVE Arcade games being played on the service today. In fact, it is being called a stand-out title for all of Xbox LIVE Arcade. “Braid,” a puzzle-platformer released on Aug. 6 quickly climbed the charts to become the No. 1 highest-rated game of all time on Xbox LIVE Arcade. “Geometry Wars: Retro Evolved 2” and “Bionic Commando: Rearmed” also have spots in the Top 10!

“At E3, we committed to re-focusing the Xbox LIVE Arcade business, vowing to release bigger and better games while focusing on quality and not quantity,” said Marc Whitten, general manager of Xbox LIVE. “The debut of the new strategy proved to be a huge success, with the Summer of Arcade making August the highest grossing month to date. But the focus on quality games doesn’t stop with the Summer of Arcade. We have plenty more great titles coming out in the next few months and beyond that we think will continue to fuel this incredible momentum.”

The service is geared up to continue on the record-breaking path with even more blockbuster titles, like “Portal: Still Alive,” “South Park” and “R-Type Dimensions,” slated to hit Xbox LIVE Arcade in the coming months.

Looks like this winter could be heating up…

Each week after this will feature a new huge title. Next week sees the release of Jonathan Blow's innovative platformer Braid, followed by Bionic Commando: Rearmed (explaining the delay), and the reinvented classic Galaga Legions. Wrapping things up will be the August 27th release of the long-awaited Castle Crashers, from the creators of Alien Hominid. That's right, a game we've been waiting years for is coming out after a game announced two weeks ago. Such is the magic of summer! Sound impressive? Wait, there's more!

During the Summer of Arcade event, anyone who plays even a trial version of these new titles is automatically entered to win one of five weekly 4,000 MS point prizes, as well as a grand prize of 100,000 points, and Xbox 360 Elite console, and a 12 month Gold subscription. Two second prize winners will walk away with 10,000 points and the Gold sub.

Definitely an interesting promotion, with some excellent games attached. It's been a relatively lackluster summer so far for Xbox Live Arcade, with the Puzzle Quest expansion being the only thing I've purchased in the past few months. Looks like they'll be making up for lost points over the next five weeks. Good for them!

Announcing the Summer of Arcade and Geometry Wars Retro Evolved 2 releases this week [Xbox Live's Major Nelson]