I saw those when I was in Asia earlier this year. They looked like just another lame special control game to me.
What I saw that was awesome - was the arcade games that used real water. For example, there was a firefighter game that had a giant LCD screen, on the screen was a burning building, and you grabbed a fire hose and sprayed out the fire with water. The Screen was obviously waterproofed, but it would sense the water hitting it like a touch screen. There was also one that was a digital version of the water gun carnival games.
I think I have photos of those games, I will probably have to dig around to find them.