As we correctly guessed, Metal Slug XX will be released this week on Xbox Live Arcade. The 1200 
title features two player local and online co-op play with six different characters to choose from. The same game has been available on the Nintendo DS as Metal Slug 7, which didn't include co-op play. A PSP version was released last year as Metal Slug XX and added that feature in, but now we're getting the complete package with offline and online co-op.
Also this week on Xbox Live Arcade is a little unique title Aqua. The game is a twin stick shooter where players control different classes of fighters. It seems air, land and sea play a large part in the strategy of the game, as players guide there ship through a gigantic naval battle that is unfolding around them. Sadly the game only supports two player local co-op through specific maps - no online play here. You can read more about Aqua over at XBLA Ratings.com - who has an interview with the developer. Aqua will set you back 800 .