A great feature if you're actually combating crime for real, but Arkham Asylum was so brilliantly realised visually speaking that it was a shame so many missed a lot of detail because they were playing the game with permanent X-Ray vision.
We saw the new Detective Mode in action and it certainly looked more in-depth but it doesn't look like it's any the less useful. It's an odd thing to complain about perhaps but we still got the feeling that when it comes to clearing out a room we'd still be tempted to use the mode to assist most of the time.
We're looking forward to seeing what kind of mechanics Rocksteady has put in place to deter people from snapping into hi-tech mode and staying there.
Our Arkham City preview also gave us a taste of the kind of thing we can expect from the game's side-quests. We saw Batman swoop in to save Gotham Radio's Jack Ryder from a beating.
It worked well but in very much the same way as any other fight in Rocksteady's Arkham franchise. That's perfectly fine as long as we have wide selection of side-quests to go with it.
Rocksteady has already said there will be plenty of content in the game that will keep you busy and every little side-mission will make you feel like Batman rather than being tacked on for the sake of it.
We don't know how much scope there will be for a wide-variety of side missions though, considering we're fighting in an abandoned mental asylum, there aren't going to be too many civilians to save.
Rocksteady seems confident though and as long as the side-quests aren't just thinly veiled versions of fighting gangs over and over again, we'll be happy.
BEHIND THE MASK
That's right, we want to see Bruce Wayne.
Since Rocksteady has always seemed pretty focused on getting the core essence of Batman as Batman exactly right, this is unlikely, but we'd like to see the developer's take on Bruce Wayne as well.
We thought the stand-out moment in Arkham Asylum was seeing Batman slowly decline into infant Bruce at the scene of his parents' death, so we know that Rocksteady can tackle the wider Batman character with some real flair.
By replacing Oracle with Alfred on the end of the comm.-link as well, there's an even greater opportunity for a more vulnerable side of The Bat to be exposed as he converses with his loyal butler and confidant.
We're also expecting another iteration of the Batcave as in Arkham Asylum - or maybe Batman will leave Arkham City at some point to head back to the actual cave beneath Wayne Manor - at which point we'd like to see him take off the mask. Nothing fancy - perhaps nothing more than a bit of a brood at the Bat-computer even - we just want to see Batman's alter-ego recognised.
Remember Hugo Strange's final words in that amazing trailer? Bruce Wayne could play a bigger role than we expect.