Not bad at all!
The game engine seems to work pretty good. The game never lagged in my face once. The relative accuracy of the targeting line is good, and the graphics are fine.
You should work on the balls color. As 'DarkIntent' said, balls are incorrectly painted (striped balls have a stripe of color, not a stripe of white). The Eight ball is way too shiny, it looks kinda blue instead of black. When you break out, there's like 2 balls that is going to move. 3 if you're really lucky. Thats a bit unrealistic, but anyways. The Computer is kinda hard to beat, but after playing a few game against it, I managed to find some trick to beat it almost everytime. ^_^ It's quite a challenge tho, cause if you miss once, or twice, the CPU is gonna putt all the balls. Still a very good game.
Overall Score: 7/10
I'd be happy to see a 'Real Pool 3D 2' ;)