You know, I was pretty dang good at those, but not too good at the pure brawling challenges.
I managed to get 3 batarangs on each challenge, but the last two were pretty rough. Very little room for mistakes, and it's tough to not make any with so many enemies. Especially when you fight multiple Titans.
EDIT:
I think something might go good here, and it's not another copy of any of the above.
It goes something like this: Person A runs to the center of the map first and unlocks a buff that gives him double damage, health regeneration, and a rank 1 Fleet of Foot boost. The downside to this cool buff? He is now highlighted on the radar. Everyone else now wants to kill him because he is gaining points every few seconds (10 or so). Whoever actually does kill him gets the buff, and around the ring we go. First person to 100(200?) points wins.
This mode would have a little free for all, a little tactical, and a whole lot of adrenaline.
P.S. - And it would also shut everyone up who's whining about not having TD, Search, etc.
They have that in Halo right? I think it's called Juggernaut? And introducing a Free For All game in a team oriented shooter just seems counterproductive to me.
EDIT 2:
And I'm sure people would still complain about no TDM/SND/Demo/HQ because Call of Duty has 'em, and damn it every game should be Call of Duty.