looks pretty solid from the previews I saw. This is NOT a stealth game, BTW. Not in the least. It much more resembles 'Predator' than it does Splinter Cell. Your objective is to kill the bad guys (notice I said kill - batman has a little more power over his enemies now that he'll be getting at least a T-Rating) and get the hostages, not sneak past cameras and avoid detection.
One of the big elements of gameplay is fear. If u KO or kill (it seemed like u had enough of a variety of moves - although it'll be a small selection to keep things simple - to do either) several enemies, and leave just one standing, he'll go crazy with fear, taunt u, fire his gun randomly wherever he thinks u might be hiding.
That reminds me - eventually, they'll catch on and try to flush u out or hunt u down. Not always, but if u make urself a little too apparent.
Also, there are apparently some twists. They hinted that a countdown wasn't really a countdown during one part of the preview, that it was rlly something else and that they wanted to keep the player guessing (not at the puzzles, but at the Joker himself).
There's also going to be an RPG-lite sort of element where u get Experience points to upgrade batman. No floating numbers tho - if u get xp, bats will fly around Batman to indicate it.
And the batman u get at the beginning won't be any wimp, even tho there's the RPG element - he'll be pretty kickass vs quite a variety of enemies. But there will be a few enemies (minibosses, bosses, presumably) that he'll need a little more skill to take out. The developers also said that the skill tree would more or less open up more combat and gear options than simple stat-ups.
All in all it looks solid, but making it for the PC didn't seem the best choice. U'd probly need a gamepad if u were gonna buy it fer the PC, since it's third person, and this kind of fighting game doesn't seem to work well on a keyboard.
Dun have a r3l33s3 date, but should soon.