The Riddler's role in "Arkham Aslym" was pretty limited. Sure, he left a bunch of riddles scattered about the island, but apart from a few taunting audio clips, you never actually interacted with the bequestionmarked gentleman in green. That's set to change with "Batman: Arkham City," which offers a much more robust Riddler experience, as evidenced by this new trailer:
Riddler trophies are still hidden around Gotham City as they were in the first game, but collecting them nets you more than just an experience bonus. As you gather more of them, you'll unlock full-on Riddler challenge rooms. These rooms, scattered throughout the city, are generally trap-filled and feature hostages in distress which Batman needs to save.
I was able to play through one of the later ones during E3, and it was indeed tricky, with rolling spikes and electrified floors. In that circumstance, it was a case of advanced room traversal, something that "Arkham Asylum" never really required. Hopefully that's not the only kind of Riddler challenge room the game will have, though. I enjoyed the more thought-provoking Riddler challenges of the first game, which required that you line up a question mark on the ground or use your equipment in unique ways. We did see some of this with one of the Riddler trophies, as you had to electrify a remote baterang to activate a gate switch, but I'm hoping these sort of tactics come into play during the Challenge Rooms, as well.
No matter what, it's nice to see yet another facet of "Batman: Arkham Asylum" being fleshed out for "Arkham City." There's little doubt that the game still has unnamed features to reveal before its release date on October 18, so stay tuned as we learn more about the Dark Knight's return.