CHALLENGE 24 - Use the Remote Electrical Charge to blast one armored thug into any other thug
How to complete: Find an armoured enemy (the type which you defeat using Beat Down, screen above). Shoot at him with the Remote Electrical Charge and with some luck he will hit another inmate while stunned.
CHALLENGE 25 - Use the Freeze Cluster Grenade to immobilize three or more henchmen at one time (Upgrade required)
How to complete: You can approach this challenge only after unlocking the Freeze Cluster Grenade. It's worth to try this challenge in smaller areas, as the enemies don't have anywhere to run. You can also search for a place where they're standing beside each other (screen above) and attack them by surprise.
CHALLENGE 26 - Use the Freeze Blast to freeze an enemy then a Batarang to knock them down
How to complete: You can approach this challenge only after unlocking the Freeze Blast. Additional description seems needless, as the name says it all. Make sure not to attack the enemy in any other way after freezing him, but use the Batarang at once.
CHALLENGE 27 - Perform a Grapnel Boost Takedown
How to complete: You can approach this challenge only after unlocking the Grapnel Gun Boost. Take a look around Park Row or the industrial District for a roof patrolled by armed enemies. Provoke the enemies by showing yourself to them and wait for one of them to approach the roof ledge (screen 1). Aim at that ledge with the Grapnel Gun and afterwards use the Boost by pressing (and holding down) A twice. If you have done everything properly, Batman won't catapult upon reaching the ledge, but automatically knock out the enemy (screen 2).
CHALLENGE 28 - Use the Reverse Batarang to knock down an enemy
How to complete: You can approach this challenge only after unlocking the Reverse Batarang. Stand above a group of enemies, aim at one of them (left trigger) and hold down RB until the aiming process finishes. Afterwards let go of RB and the Batarang will automatically circle the enemy and knock him out from behind.
CHALLENGE 29 - Kick an enemy while riding on the Line Launcher (3 required)
How to complete: You can approach this challenge after unlocking the Line Launcher. Stand on the same level as the enemy you want to knock out and aim the line at him. After the ride begins, make sure that Batman will hit him (it's best if the inmate doesn't get alarmed too soon; screen above). Repeat this two more times.
CHALLENGE 30 - While riding on the Line Launcher towards an unaware enemy, use the Takedown attack to drop down and knock them out
How to complete: You can approach this challenge only after unlocking the Line Launcher. Stand on the same level as the enemy you want to knock out. Aim and fire the line. After the ride begins, wait for Batman to get nearby the target (screen above) and press Y for a knockout.
CHALLENGE 31 - Catch a Remote Batarang
How to complete: this trivial challenge implies throwing a Batarang and making sure it returns to Batman. You can perform a full turn or just turn the gadget around by pressing the left and right trigger at the same time.
CHALLENGE 32 - Fly a fully boosted Remote Batarang into a thug and send him flying through the air
How to complete: Throw a Remote Controlled Batarang and hold down the right trigger to make it fly faster. Lead it onto one of the enemies. The hit should be strong enough to send him flying automatically, so you don't need to worry about hitting him at a specific angle.
CHALLENGE 33 - Use the Freeze Blast to freeze an armed enemy before taking him out
How to complete: You can approach this challenge only after obtaining the Freeze Blast. Aim at a single armed enemy, use the Freeze Blast and afterwards approach hi and press Y for a knockout.
CHALLENGE 34 - Use the Smoke Pellet to disorientate an armed enemy and follow up with a Takedown
How to complete: Look for at least one armoured enemy and land beside him. Once Batman get noticed, press Y to let out a smoke pellet, quickly approach the enemy from behind and press U for a knockout (screen above).
CHALLENGE 35 - Disarm an enemy using the Batclaw disarm (3 required)
How to complete: Completing this challenge requires the Batclaw disarm upgrade. Locate a single armed enemy and after getting near enough, press the left trigger and Y. Repeat this two more times afterwards.
CHALLENGE 36 - Use the Disruptor to jam the gun of an armed enemy and then get him to try and fire
How to complete: You can approach this challenge after unlocking the Disruptor and the Jam Firearm upgrade. Locate a single armed enemy and equip the Disruptor. Press the left trigger and then the right one and wait for the bar to fill up (screen above), informing that the gun has been jammed. Jump down and stand in front of the enemy, so that he tries to shoot Batman.
CHALLENGE 37 - Use the Remote Electrical Charge to temporarily disable a backpack Jammer device
How to complete: You can approach this challenge only after unlocking the Electrical Charge. Additionally you will have to find a group of enemies with at least one jammer device (screen above), the perfect place for that being the main subway station. Shoot a charge at the enemy thanks to which the jammer will stop working for a while.
CHALLENGE 38 - Take down an enemy using the Sonic Batarang
How to complete: You can approach this challenge only after unlocking the Sonic Batarang and the Sonic Shock Batarang upgrade. Throw a Batarang and make it hit the floor or a wall beside an enemy's patrol route. Once an enemy gets beside the Batarang, press the left trigger + RB to detonate the gadget.
CHALLENGE 39 - Perform an Inverted Takedown from a Vantage Point
How to complete: It's a very simple challenge which you will probably complete during the main story. You need to reach one of the rooms in which you need to act from the shadows and with vantage points. Reach one of such points, wait for a guard to get beneath you and press Y for a Inverted Takedown (screen above).
CHALLENGE 40 - Perform a Knockout Smash (5 required)
How to complete: Completing this challenge shouldn't be hard. Approach any enemy from behind, helping yourself by crouching down if you need to. After getting beside him press Y for a silent takedown. Repeat this four more times.