Terrible graphics, sound quality and car selection make a bad game worse.
Single race (you know what this is)
Championship (get given a car then race against identical cars)
Time trial (my favorite mode. Beating a set time for each track rewards you with new decals for your cars.)
And Multiplayer (but no-one to play with)
The Good:
Licensed cars with real life decals, albeit from the British GT championship that no-one really cares about
Tracks are well designed, look good compared to the cars and clearly draw inspiration from real world tracks such as Daytona, Laguna Seca, Silverstone and Snetterton.
One of only two racing games I know that have the Mosler MT900 (this and Race Driver 3)
The Bad:
There are only 5 cars, that are all racing or road versions of the Mosler, or Ascari KZ1
The graphics of the cars look terrible, with no textures at all
The AI isn't too but but still leaves a lot to be desired
Even when not accelerating, the ambient engine sound is dreadful
Every so often, the game will crash for no apparent reason, and with no way to save progress during a long championship, this can be very annoying.
Overall GT-R 400 is a game with good tracks and bad everything else.