Well, upon first play I had a crash to desktop. Just did some experimenting with it, got a little further in the race, seems to stutter/crash when more than 2 cars are on the screen. Ran ok at minimum graphics settings, while I was the only car on screen. When I caught up to the pack and started to pass other cars, it hung and eventually crashed to desktop. Could be a nice arcade racer, hard to tell when I can't finish one race. :(
Update 07-27-15: It runs ok in Yosemite. So as gameplay goes, physics are really bad; sometimes the cars oversteer and sometimes they understeer. Very hard to control. There are only 3 tracks, but lots of cars. I still only give it 3 stars, there are other better racers available.