Unsurprisingly GTA IV faces little in the way of home console competitors this week. Expected to generate perhaps as much as $400 million in first week sales, reviews have started pouring in and they’re universally pretty fantastic - the game currently has a metascore of 100 on review aggregator Metacritic, having received a perfect score from numerous publications.

“Expectations were so high for Grand Theft Auto IV that one of the biggest surprises is that it"s managed to meet them,” writes IGN, which gave the title 10 out of 10. “That it"s also gone on to confound these is truly a marvel, and the game"s Liberty City is nothing less than one of the greatest videogame worlds yet conceived.”

Our sister site CVG, which gave the game 95 percent, is only slightly less gushing: “Coming back to our original conundrum, GTA IV has its flaws as a game, like the sometimes problematic auto-aim shooting or the massive difficulty jump when you get to the final ten missions. But as an all-round experience it"s truly, hype aside, a standout experience of gaming in 2008.”

Also out this week is Sega’s multiplatform title Iron Man, based on Marvel Studios" feature film of the same name starring Robert Downey Jr. and Terrence Howard. How well the game will sell is unknown, but at least one games industry analyst expects the film’s box office takings to take a hit due to GTA IV’s release.

Mario Kart Wii, which has recently topped the Japanese, European and Australian charts, should also sell heavily this week following its release Sunday just gone.

Releasing this week:

Baseball Mogul 2009 – PC
Strategy First

Brain Voyage – DS
Eidos

Chameleon – PSP
UFO Interactive

Grand Theft Auto IV – Xbox 360, PS3
Rockstar

Great War Nations: The Spartans – PC
Dreamcatcher

Iron Man – Xbox 360, PS3, Wii, PS2, PC, PSP, DS
Sega

Let"s Pilates - DS
Konami

Let"s Yoga - DS
Konami

River King: Mystic Valley – DS
Natsume

SNK Arcade Classics V.1 – PSP, PS2
Crave

Toy Shop – DS
Majesco