In this mission you have to repair the chopper (to do it you will have to find three parts). First of them is just near the chopper. Use the bricks on the ground and after that move left and throw Batarang at two grippers above the doors (picture). When they fall down get inside, destroy the machine and use bricks to create platform with power suit for Batman.
In this suit you can use rockets to destroy silver bricks. Move to the searchlight standing on the right corner and destroy it in this way (picture).
Use bricks to build platform with magnetic suit for Robin. Stand near "Oscar" neon, aim at blue horizontal brick and press K (picture). Do it the same with the second horizontal brick and after that use blue pipes to get on the higher ground.
Move left and shoot at the orange grapple (picture). When you get to the higher floor jump on the pole on the left and move up.
When you get higher use magnesium on the blue bricks on the right side (picture). After that use blue bricks to get on the right side of the building.
Eliminate all opponents and use magnesium to lower the lift (picture). It will provide transport for Batman and give you parts to repair the chopper. Use lift to get Batman on the higher floor, move him to the orange holder and pull it by quickly pressing K. Then use Robin's magnesium to pull down the ladder.
In the next location use Batman's rocket to destroy silver brick and use Robin's magnesium on the top (picture). Then use hook to get on the higher floor. Move left, destroy searchlight with rocket and use bricks to create an rope.
Use hook at the holder (picture) and when you get to the higher floor start heading right eliminating the opponents. After a while you will get to the blue brick. Use magnesium at it and then use hook at the handle to get on the platform on the right.
Use Batman to pull the handle (picture) and get the last part of bricks for the chopper. Now you just have to get back on the ground and repair the machine.
In the next part of the mission you will be chasing Joker. Your task is to aiming at his boat and firing. After every destroyed heart you will also have to face with other enemies (boats and choppers) - just aim at them and pull the trigger (picture).
In the next section destroy part of the digger on the left and use bricks to build a cannon and push the green part of the lever (picture).
After that move to the top right corner of the location and use bricks to build a Joker's face on the wall (picture). Then launch rocket at his teeth and use blue bricks to fill hole on the left side.
Get Robin on the top, destroy bricks on the highest platform and use magnesium (picture) to pull out two blue poles.
The last thing you must do to defeat the Joker is destroy the car. First launch rocket at the hood, then open it with magnesium (picture), after that launch rocket at the engine and in the end build large hammer and use it at the Joker.