It can be preety hard to complete batman 100% as there are a few sneaky little things that you need to do to complete the game 100%.
1. Throughout the Island The Riddler-Edward Nigma has hidden 240 riddles and trophies throughout the island, you must find them all and solve all of the riddles. You can find secret maps that show the general area of the riddles some may seem to be in a room but remember that there are underground cave and sewer systems in the island...
2. There are Hundreds of chattering teeth throughout the island, funnily enough you have to destroy them all and it can be a pain in the *** to have to go back and kill them all when you find this out.
3. There are interveiw tapes of famous villians throughout the island and you must find them all, bearing in mind some of them will help you solve the biggest mystery.
4. You obviously have to complete the story mode but challenge mode can help you get gamerscore on xbox, by achieving trophies.
I hope these tips will help you complete the game, if i helped you please click the thanks button.
The simple way to see what challenges you have done is to look them under the ridler cahllenges menu, or find the seret maps which tell you where they are.