The original Test Drive Unlimited was great, but it rightfully bombed in reviews due to some really bad technical issues. Some of the car characteristics were really bad and off the mark, and the game suffered from an engine issue that was a problem other racing games had solved long ago;

On long slopes, the geometry of the road didn't curve properly; the angle would have a polygonal jagging issue. This was most likely to shave off performance cost on the 360. Other games had already solved this issue by effectively smoothing angle changes, but TDU did not do anything of the sort. The result was that on hilly terrain cars would constantly bump around and lose traction due to weird unexpected air-time. Some cars were affected far worse than others, particularly super cars had a bad time.

I loved TDU, I loved cruising around in my Shelby Cobra and doing the one-hour tour around the island for decent money.

But the list of flaws is pretty long, and the technical issues made it a nonstarter for anything competitive.

Same, but the demo didn't really give a good impression.