Some of the Circuits of Racing Universe included.
Big Forest: Original Virtua Racing Course and on one of the outdoor planets. Features the replay theme from Virtua Racing Deluxe as it's main theme.
Joypolis 2020: Originally from Daytona USA 2: Has I Can Do It as it's main theme. On Another Outdoor Planet out of the 20 Outdoor Planet Courses.
Sega Rally Challenge: Exclusive to Team WDP: Features Getting Muddy as it's main theme and is a metropolitan version of all the Sega Rally Championship Circuits. Features Airdancers as well.
Daytona Challenge: Team MK's Circuit, features a metropolitan version of all the circuits from Daytona USA, the 1993 original.
Ridge Planet: Original circuit for team Ridge Racing. Based on the Circuit from the original 1993 Ridge Racer. Features the Ridge Racer theme as it's main theme.
Long Metro: A Circuit Exclusive to the Real Racing team, featuring a Palace similar to Buckingham Palace and is probably the toughest of all the races. If you win this race, the awards ceremony takes place on the Palace Balcony Podium.
As you race on some of these Circuits, you may spot the odd character making a blink or you'll miss it Cameo, on the Sega Rally Challenge Circuit, you can see Bold from Farthing Wood and some buddies of his cheering you on in a viewing area in the tunnel. With his actual voice as well. On Long Metro, you can see King William and his Wife the Vice-President waving from the palace. As you race against Lewis Hamilton in the City Streets. You can see Reiko Nagase on the Screen of the Ridge Planet race as well. On the Original Metro Circuit, you can see Yazaki and Christman on a balcony somewhere.
The game uses a special Sega-Codemasters Racing Engine that is a mix between Ridge Racer's, Daytona USA's and Grid's Gameplay, but uses the Daytona USA 2 Pit Stop Engine.