Even though there are a few examples of first-party titles being released for other formats, like Microsoft's Ori and the Blind Forest and Sony's MLB The Show 24 (and the upcoming Marathon), it isn't very common at all. As a result, it was pretty big news in early January when there were rumours claiming that the Xbox exclusive titles Sea of Thieves and Hi-Fi Rush would be released for PlayStation and Switch.
Several trustworthy journalists and insider vouched that this will actually happen, and now we've got more hands-on proof. Thanks to Reddit data-miners, we now know Hi-Fi Rush includes T-shirts intended for PlayStation (a blue with the text "I'm here baby") and Switch (a red with the text "Rock out Anywhere") owners to use with the main character Chai. There is a green one for Xbox gamers as well, saying "Shadow Dropped" and a grey for Epic Games Store that reads "This is simply Unreal Epic".
With the cat pretty much out of the bag, we assume a formal announcement isn't too far off, and it will be interesting to see how Microsoft will handle the fact that all gamers will now wonder if all Xbox exclusives could potentially be released for other formats.
