The boss battles are kinda unimpressive, with the exception of Scarecrow. Fighting Bane and Joker was nothing special, as we did it many times throughout the game against other thugs on titan.
But they did something really cool with Killer Croc, with all that tension going on and you didn't know where he'd strike next, having to act carefully, and having Ivy's plants fully powered attacking you and changing the scenary was also cool. Regarding the length, I thought it was just about right.
The game's price is certainly well earned. The gameplay is just too good. I may have played through it like 7 or 8 times, if not more.