Sony is thought to have issued a number of online surveys asking fans what they thought of All-Stars Battle Royale as a title, and whether it fits the game, reports PlayStation Lifestyle.
Separate sources suggest that the Sony-themed fighting game, which is being developed by SuperBot Entertainment, will be unveiled at this year's E3 event in Los Angeles.
Rumours of a Sony version of Super Smash Bros. surfaced last year. The game was reportedly in the works under the name of Title Fight.
Uncharted's Nathan Drake, Twisted Metal's Sweet Tooth, Killzone's Colonel Radec, Fat Princess, Kratos, Sly Cooper and PaRappa the Rapper are among the characters expected to feature in the game.
SuperBot Entertainment designer Chris Molina fuelled speculation about Title Fight with a Twitter post suggesting that Sony's 'Michael' commercial, which features a range of its mascots, was "vaguely foreshadowing" his studio's "soon-to-be-announced title".
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Watch Sony's 'Michael' commercial below: