Alright, so I know of a few people in person, and even more on the internet that bought this game and are upset with it. Well, you bought a game based on Fast and Furious that started at $40. What were you expecting?
Fast and Furious: Showdown is a typical Need for Speed copy game, with a few added twists. Now, to be clear, I only played the story mode, I never tried any of the challenges of co-op gameplay. There are a variety of different levels throughout the game, typically similar levels are spread out enough to help prevent too much repetition.
All of the missions are very much movie themed, some of them straight out of the films. There are a few basic "racing" levels where your entire goal is just to get in first place, as well as variations of that such as elimination runs. They all are from the movie, or star characters from the movies.
For example, a few missions are simply just "outrun the cops" missions. During the fifth film, they pull a giant safe with a car. You get to do that while running from the police. It is actually kind of fun. There are other combat style missions. One person drives, the other shoots. There is a small variety of weapons, but I felt there were enough to keep it interesting. Also, there are two missions featuring the vehicular combat cars from Fast and Furious 6. I don't know what to call them, but they are the ones that flip cars into the air. those missions are pretty great actually.
If you are craving a racing game, there is literally nothing here you aren't going to find elsewhere done better. However, if you are really into the whole "Fast and Furious" thing, this is probably for you. It builds a little more on the characters and is a great introduction to the sixth film. Also, every level is built to be played with two people. There are always either two cars, or one shooter and one driver. I didn't get a chance to play co-op, but I can't see how it wouldn't increase the fun of this game tremendously.
Like I have said many times before, it isn't a perfect game, but that is what Red Box is for. I beat the entire story mode in under six hours. I got off work around 9:00 PM and was finished with the game well before 4:00 AM. It costs me $2 and it was totally worth that.
I don't recommend it for the full price, but it is going to drop really fast really soon. I do recommend it to any die hard fans of the series, and I know you are out there. It's got a fun story for fans of the series and familiar characters. I would recommend it for the $10-$20 range.