Sunset Overdrive appears to have co-op play for up to eight people, according to a since-pulled listing on the Xbox One store.
The page below appeared on the Xbox One store before it was nuked. Luckily, MP1st capped it for all to see:
The text mentions a co-op mode called Chaos Squad, which sees player teaming up to tackle mutant enemies.
Microsoft hasn't confirmed this yet, but its E3 2014 conference is kicking off tonight, so we may hear something on the matter. You can watch the show live here.
Meanwhile, you can check out this Sunset Overdrive city video, which shows how Insomniac Games crafted the setting of Sunset City to make it fun.