Microsoft says downloadable games must arrive on XBLA at the same time as rival platforms or it will threaten not to publish them at all.
In an interview with Eurogamer, Microsoft’s VP of interactive entertainment business for Microsoft Europe Chris Lewis said the reason for this was all about protecting its space in the market.
“We're a little biased, so obviously we're going to look to protect our own space as best we can and get exclusivity,” he said.
"You can be very confident we seek to maximise our own advantage to ensure the playing field is even, and [that it] certainly plays to our advantage wherever possible.
"As you can also imagine, our partners have to be mindful of the relationship they have with all platform holders, and they need to be equitable. But there are contractual situations where we get agreement with different people to do different things."
Microsoft's Content Submission and Release Policy states that titles for Xbox 360 must ship at least simultaneously with other platforms, otherwise Microsoft reserves the right to not allow the content to be released on Xbox 360.
Lewis added: “Through what we have available on Xbox Live we are able to offer things other people can't offer, which allows that exclusivity and unique elements to it that might not otherwise be available elsewhere.
"We just want what our consumers want from us. We want the quality bar of what they experience from us to continue to go up. And despite the fact it can be irksome to have such strong competition all the time, it actually does keep us on our toes. It's great for everyone, and it makes for a very healthy race to higher and higher levels of quality of game experiences."