Arkham Asylum question (spoilers maybe)

[Peabob]

I just beat Poison Ivey and the Joker now tells me to go somewhere for the "final surprise" so I'm guessing it's the last area of the game. My question is at what point does the game stop you going back over the rest of Arkham to collect trophies and solve riddles etc as I really want to 100% this game and grab a Platinum trophy. Or does the game let you continue exploring after completing?

 

[Heathrow]

You can explore after completion.

 

[TheNamlessGuy]

DELETED

 

[Peabob]

Thanken you

 

[PhunkyPhazon]

Only odd thing is that you can't repeat the final battle once you've done it. Or at least, it didn't let ME do it for some reason.