Yes it's on the PSP and yes there's no career. but it is GT and it does what people have wanted for years, GT on the go.

User Rating: 8.5 | Gran Turismo: The Real Driving Simulator PSP
OK, ladies and gents, the only real way to distribute the truth of the game is to start listing of pros and cons, THEN adding in the details, so here goes.

Pros of GT for PSP:
1. An incredible number of cars, all detailed in traditional Polyphony fashion.
2. 45 actual tracks, 73 including reverse layouts, may seem small but is helped by another GT tradition, randomly chosen competition.
3. The tracks in the game give a nice range, from the Beginner Course to the New York city track to the Ice Arena all 13 miles to the Nurburgring Nordschleife.
4. an "old" spin with the new cars, each in-game day gives you only four makes, but say for example MAZDA shows up two days in a row, the line-up is different from day to day.
5. Ferrari and Lamborghini, finally.
6. The challenges, unlike licenses, aren't required for everything.
7. On a plane, on a train, on vacation, on location, it's GT on the go, what more do you want?
8. Graphics rivaling the PS2 installations.

Cons of GT for PSP:
1. Yes, 35 tracks is still small.
2. Yes, no career mode defeats the purpose somewhat( and I have something to say on that.)
3. Same goes for the lack of tuning options.
4. 4 cars on track as compared to traditional 6.
5. No real unlockables
6. No designated races, series, enduros, etc.

So ther are good bits and not-so-good bits as there are in nearly all games, but you have to go through the thinking of the game. Look at the facts, Car Sharing, Car Trading, Four-way link racing for friends to race against each other. This isn't a traditional GT game, it's a GT game with appeal to the masses. It's not a game meant to be played to the level of obsessive, but one of the few new games that can actually be classified as a "pick up and play" type of game, and the only ones who will be dissapointed are the people who play GT1-5P every hour of the day.