Are any of the Riddler Challenges missable?

#1GrimeyvillePosted 9/11/2011 8:25:07 PM
I distinctly remember the first time I beat this game that I missed a Riddler challenge, and it seemed like I couldn't go back for it after beating the main story. What are the challenges that can be missed so this time, I can get 100%? Does anyone know, and thank you.
Enchantment? ...ENCHANTMENT! :-D" -Sandal, from Dragon Age: Origins
#2NavexPosted 9/12/2011 3:57:01 PM
"You can do anything you want in life. Unless Jay Leno wants to do it, too."
- Conan O'Brien