I played the game, and I must say, it's just like playing the original Underground with a steering wheel and a 6-gear shift box.
It ran pretty smoothly. The only modifications to the graphics is that there was no motion blur when you were driving without nitrous, and when you hit the nitrous, it blurred like regular, but it was toned down just a little bit. They also added colored gauges, instead of the boring bright LCD blue like the original. The gauges aren't custom like in NFSU2.
All the courses from the original are there. It has a card system like Initial D and Midnight Maximum Tune, but I didn't buy a card to save my data. There are 3 modes. Single race, Career, and Tournament. I only did the single race mode against my friend. Speaking of AI, they play on a difficulty level between medium and hard, and they can get pretty frisky. The only gripe I had about the in-car view was that there was no rear view mirror, but there is a look back button that I barely pressed. There is an E-Brake that you can press which is located on the gearbox so you can do your powerslides.
Unfortunately, the style points don't feed into your nitrous meter like in NFSU2, which I forgot about time to time when I was playing. I guess I got a bit too comfortable with the NFSU2 nitrous system. The only real changes to gameplay is that there are a total of 8 cars to race against. But, if you're racing against friends, it'll only count what place you are according to the linked cabinets. I had a lot of fun playing against my friend.
There are a few cars to choose from though, but then again, it's only an arcade. They have preset designs of the cars too choose from as well. Nissan wasn't one of the manufacturers to choose from; you had to get a card to choose the car you really wanted. But I didn't care. From what I can remember, the cars you could choose from were the RX-7, Eclipse, Civic, Integra, a Supra, and another one, but I forgot which it was. I'm guessing that with the card you can customize your own car with the style points you get from racing.
While I was choosing a course, it did say that the cabinet was a testing cabinet, so that might mean the game is currently being tested as a beta. The game was very polished, and a lot of fun to play. All you Need For Speed fans, Underground or not, should definitely check it out.
EDIT: Here are some pictures from IGN -
