Addictive, but flawed.
The graphical execution is the best I've seen in a city/transport sim - not only does everything look good, when you zoom all the way in, you can click on any car or pedestrian and find out everything you'd like to know about that individual. A bit more freedom with the camera controls would have been nice, as I frequently found myself unable to zoom out far enough when planning routes. The set viewing angles don't detract much from the game, but it does feel a bit clunky and antiquated to have to resort to the keyboard to control the camera.
It's easy enough to get off to a good start, and it remains fun for awhile, but you inevitably become a victim of your own success - the streets become choked with public transport vehicles. As your fleet ages, operating expenses outpace your ability to increase fares, and the economy chews you up and spits you out. Just like a real public transport company!
The thing that really irked me with this game were the flawed behaviors of street traffic. The worst is how cars fail to change lanes to pass loading & unloading vehicles, creating backups that eventually lead to near-total gridlock and render the game frustrating and unplayable. That's a shame, because there really is a lot done right in this game