It seemed they were doing SOME detecting in Shadow the Hedgehog, too, though it was never made quite clear what they were trying to take data from Eggman's and the ARK's computers.
I can also see the Chaotix in one of those kinds of investigative adventure games, though.
What I could also see would be a game starring Rouge along the lines of "Metal Gear light edition," so to say. Like, sneaking around and all that but without 2 hours worth of opening cutscenes, much as I personally like Sonic cutscenes. :B