As imaginative as the courses are, their layout also leaves a lot to be desired. Bumps are placed on the track so you invariably jump into a bend, while the corners themselves seem to be on a completely different radius to the quad bike's rather stilted turning circle.
All this conspires to make Xtreme Quad Racing as unplayable as it is attractive. It's perhaps good news for Darxun that it worked out this way around, as the graphics would be harder to fix in an update, and there's a possibility that the gameplay could yet be salvaged with some serious work.
But right now, it's far too crude to recommend.