The Lost Watch 3D is an animated wallpaper with a watch in it. Story has it that an absent-minded traveller dropped his watch when passing a river. Now, you can see that watch as your desktop wallpaper. The watch is still working and you can see the second, minute and hour hands moving. The water of the river flows and this effect is very well made. Every now and then, you will see leaves and other objects flowing past the watch in the river.
When The Lost Watch 3D is running, you will see both a dock icon and a menubar icon. You can access the settings from the menubar. From there, you can specify on which monitor you want to run the wallpaper, whether or not you want to see the dock and menubar icons, select the color scheme and which sounds you want to hear. You can also load an image and put it inside the pendant by the watch. Or you can choose to hide the pendant.
There is also a screensaver mode, which you can access from the menubar and dock icons. This will put the animation on all your monitors by default.
All in all, this is a very nice wallpaper and screensaver. I wouldn't run it constantly on my Mac because it makes it very hot and a bit slow.