More challenging it's not always funny. If you have the possibility to do spectacular thing like... using fireworks to distract the enemy (like in tenchu) it will be funnier than going behind the enemy to perform the K.O. move. They are great but when you have do that more than 25 they are repetitive moves.
An other thing: My level of english is not very good but... i postes that the noisy-useless gadget is a s...