I still need to find stuff in the fucking elevator shaft in Intensive Treatment... and I'm too proud to look up walkthroughs... especially as I find these tend to be kinda shite.
That said, I liked the Riddler's challenges (mostly). There was one I was going insane with trying to fine- it's in the first No Grapples For You sewer, and then I randomly got turned around, climbed an unnecessary wall... and there was the fucking green dot I'd been hunting for hours of gameplay.
After I finished say "For Fuck Sake!" rather loudly... well, it felt like I'd actually achieved something. Plus, I don't know if you noticed, but you get a decent amount of XP for the Riddler's challenges.
I also really appreciated the comic references, even when it referred to villains I wouldn't have been very familiar with. I hate to admit that it took me a while to figure out who "Tommy Eliot is on the surgical team" was referring to as Hush took place during my hiatus from comics.
Damn fine game though. Playing it again now!