From the Super Mario Wiki
The race takes place in part of a plaza and the pier. The major feature of the track is the drawbridge before the end of the course connecting the pier and the plaza. The bridge rises and lowers periodically during the race. Piantas cheer the racers in many sites along the track.Delfino Square reappears in Mario Kart Wii in the Banana Cup, with the layout and music exactly the same, but with updated graphics.
The track will start in a straight path, leading racers to turn around a fountain. The track then runs along a narrow and bifurcated alley with some Item Boxes. Once past the alley, players cross a stone bridge and reach the pier with some crates serving as obstacles. If a racer crashes at high speed against one, this will break up, often revealing a Mushroom or a Banana peel. While the players are running around the pier through a sharp corner, a lifting bridge in the other side of the pier is covered in Dash Panels, allowing players to gain more speed, even in midair. In Mario Kart Wii, it is possible to perform a trick while the bridge rises. The track leads the racers back to the straight street, where the finish line is found after running through a wooded green zone of the town.
Delfino Square contains two main shortcuts the player can perform. The first shortcut is located right before crossing the stone bridge. Turning off to the lawn and the tree, a racer can jump and land to a wooden dock near the pier, shaving off a few seconds. It surely works if having a Mushroom or a Star on hand. The second shortcut is found in the pier ahead the corner. Hidden by a pair of crates, a narrow alley covered in dirt deals racers a slight advantage over their opponent. Just as the first, the latter requires a speed booster to run efficiently over the mud. However, taking no care about the consequences, players may end up leading off to the sea when passing to the other side by excessive speed.
In Mario Kart DS, the Missions 2-1 and 3-2 take place here. In mission 2-1, the player must destroy 10 wooden crates scattered around the area of the shortcut and in 3-2 pass the 5 doors in order, whilst in reverse.
Just before the first bridge, the player can veer to the left and use a Mushroom to jump over the water diagonally and land on the docks past the first bridge.
After passing the first bridge and making a left-hand turn, there will be a hidden passage on the right, which is past some crates. This off-road shortcut can heavily slow down any vehicle, regardless of off-road statistics, so a Mushroom or a Star is required to get through it quickly.
Mario Kart DS
Mario Kart Wii
In Mario Kart Wii, a tournament took place on this track. Players had to do a time trial, which added Goombas, crates, and dead-end routes. This tournament was the first tournaments of August 2010, and later repeated as the first tournament of January 2012 and the second tournament of March 2013.
Names in other languages