Rock Paper Shotgun's Lewie Procter claims to have had a Steam version of Ms. 'Splosion Man spontaneously burst into his library, only to be replaced soon after by a listing called "ValveTestApp105420." A screenshot captured by RPS shows greyed-out Achievement images that depict Ms. 'Splosion Man, further suggesting that it's a future Steam offering that got out a bit early, and not just a completely random error.

Ms. Splosion Man's initial announcement came without a platform listing, leading to speculation then that it wouldn't be an XBLA exclusive. And as far back as 2009, the developer was saying there was nothing holding the series to XBLA but convenience. We've reached out to Twisted Pixel to find out when or if this mistaken reveal will lead to a real one.