The playable Joker challenges in Batman: Arkham Asylum are exclusive the Playstation 3 version of the game, but my criticism of them is not due to the fact that as an XBox 360 owner, I can't play them. I would feel this way even if they were an XBox 360 exclusive.
The playable Joker levels are so, so wrong. It's not that they're completely out-of-character for the Joker, which they are, but mainly because they diminish Batman's abilities by making them reproducible by a lanky, undisciplined lunatic. See for yourself:
I appreciate the fact that they gave him a gun and electric hand buzzer which he uses occasionally. It shows that they tried, a little, to make these stages consistent with who the Joker is. But it's still obvious that they basically re-skinned Batman as the Joker, retaining the fighting mechanics. So now the Joker has striking and countering skills that rival those of Batman, who honed his skills over years of intense training and extreme mental and physical conditioning. It does not make any sense and just looks ridiculous.
If they were going to do this -- which I don't think they should have -- they should have given the Joker meager hand-to-hand combat skills. Let him keep the gun and electric hand-buzzer and use them a lot more. Give him henchmen to do most of the fighting. Yeah, that would have been more difficult to execute, but if something's not worth doing the right way, it's not worth doing.