Liquid Force DLC gives us 20 bonus puzzles that make use of water element. From what I know, this add-on was exclusive to PhysX hardware in some way before being made available to everybody. Can't find good enough info though, so not sure.
But the thing is that water will most likely lag your computers down to 5 FPS, making you spend a lot of time to see if your solution works or not. Maybe it needs PhysX hardware. Or maybe it's unfriendly to AMD stuff. I am not sure. But watch out, there is no guarantee that it will work good, after all I and many/some others have trouble with it.
The 20 puzzles also seem to be quite simple, as bonus to show us what water can do. No instructions, you will not hear professor here. There is only 1 or 2 mandatory objectives, no bonus ones. So it's quite simple, just to show off.
And once again some puzzles can't be solved properly. At very least two of them, where gears are placed just one step too far from each other, so you can't connect them, unless you just make game solve it for you with "reveal" hint, proving that it's the correct way yet it doesn't work for player.
So yea. Technical stuff ruining DLC. Otherwise, if water doesn't make you lag, then it's cool. I gotta say, liquid physics is awesome thing to play with.