Mario Circuit (マリオサーキット Mario Sākitto?) is a playable stage in Super Smash Bros. Brawl and Super Smash Bros. for Wii U , where in the latter it is called Mario Circuit (Brawl) (and was later renamed to Figure-8 Circuit in Super Smash Bros. Ultimate) to distinguish it from the similarly named new stage.
The stage has a simple layout, with a one base platform that extends all the way off the stage, and three floating platforms above it, arranged in a trapezoid shape. Frequently, Shy Guys in go-karts will drive from the background through the stage, alternating between driving below the platform towards the screen, and jumping over an upper track across the stage. Players are alerted by a warning arrow when they go over the track, similar to that in Onett, while when the Shy Guys drive below, they can be seen beforehand, as in Port Town Aero Drive . They are also marked on a map in the upper left corner. If characters are struck by the karts, they will take damage and neutral knockback and can even be Star KO'd at higher percentages. Additionally, the screen in the background will show the location of the Shy Guys on the circuit, making it possible to avoid the racers. The Shy Guys can be attacked and sent spinning out to the side of the screen.
Interestingly, there are graphics for the entire track. Visuals are inaccessible, even when pausing and changing the camera angle. However, such angles can be viewed by hacking.
This was the last stage that was first shown in trailers to be confirmed on the DOJO!!. Over a year had passed since its initial revelation, making Mario Circuit the stage with the longest duration between its trailer and DOJO!! confirmations.
Mario Circuit is banned in tournaments due to chain-grabbers being able to chain throw an opponent off of the stage's sides. In addition, the cars are overly powerful stage hazards, and gameplay centres around avoiding the cars, as well as throwing opponents into them.
Mario Circuit is a track that is in every Mario Kart ever since the original Super Mario Kart; however, there are only a small amount resemblances in this stage to any of the Mario Circuits. One of these resemblances is in Super Mario Kart's Mario Circuit 2, which has a jump that overlaps another part of the track. The Shy Guys in this stage having to jump over the road onto to the other side could be a reference to Mario Circuit 2's jump. Another resemblance is that in Mario Kart 64's Mario Circuit there are giants mushrooms for decoration. Tall mushrooms can be seen in the background of this stage, but the mushrooms are much thinner and taller compared to the ones in Mario Kart 64.
The overall design of this stage resembles Figure-8 Circuit in Mario Kart DS. Figure-8 Circuit features a seating area for spectators, pipes in the background, and giant block structures (which originally appeared in Super Mario Bros. 3). Also a small sign that say "Nintendo" is seen in Figure-8 Circuit. The "Mario Circuit" sign at the starting line is also the same from the game, except in Mario Kart DS it only read "Mario". All these features, including the "Nintendo" sign, are retained in this stage, but Figure-8 Circuit only had one seating area while this stage features two. Figure-8 Circuit also did not have the chicane before the straightaway that passes under the main stretch. Also in Mario Kart DS if friends wanted to play Mario Kart DS together but some didn't have Mario Kart DS, they could still connect together through Download & Play; however, the people who didn't have the game have no choice but to play as a Shy Guy. This stage features the drivers as Shy Guys and this could be also be a reference to Mario Kart DS. The trees that have faces in this stage are possibly a reference to the trees in Mario Kart: Double Dash.
The design of the giant screen in the background is based on the map that was displayed on the DS Touch Screen during races in Mario Kart DS. Pressing the "Y" button or tapping the screen with the stylus gave you this view, along with the location and position of every racer. All these features are retained here.
- In the trailer that originally revealed Mario Circuit, the Shy Guys were all driving white karts and the screen in the background was totally blank. Since then, the radar has been added to the screen and the eight Shy Guys participating are now paired, with the kart colours being either green, blue, orange or white, suggesting that the stage is part of a Team Race. Every Shy Guy is still bright red, though.
- When the announcer finishes the 3-second countdown to the battle, the arena's corresponding song will play when the match officially starts. This refers to the Mario Kart series itself, as the music for a racetrack or battle arena would begin immediately when Lakitu finished the countdown to the race or battle.
- Players can affect the way the race turns out. If the player attacks or fling themselves in front of anyone except the Shy Guy in the lead, the leading Shy Guy could get so far ahead, that as it flies over the stage, the others are coming below it.
- When a Shy Guy is hit by the player, it spins out until it is off screen, meaning if the player hits one on the far right side of the stage, it will spin out until it goes off screen on the left side.
- If the Ice Climbers use their Final Smash, Iceberg, on this level, it will have no effect on the karts, as they will simply drive straight through the ice. The same goes with Jigglypuff's Puff Up, since its body expanding will let the karts go through it instead of being pushed away. Similarly, the karts are unaffected by bumpers. Cook Kirby does not have any effect on them because they are obstacles.
- If Andross is released from an Assist Trophy, the lower part of his face will be below ground.
- In Mario Kart DS, on the Touch Screen map, the logo of a particular cup will float about underneath the map and names (for example, multiple mushrooms will float around for the Mushroom Cup, stars for Star Cup, and so on). In Brawl, the symbol of the Super Smash Bros. series is displayed instead.
- In Mario Kart DS, it is impossible for every player in a race to be Shy Guy without the use of an Action Replay code, as the player who started the room must be one of the twelve other characters. (Mario, Luigi, Peach, Toad, Yoshi, Bowser, Wario, Donkey Kong, Daisy, Dry Bones, Waluigi and R.O.B.)
- If a Giant Special Brawl is being played and Jigglypuff uses Puff Up in the centre of the arena, it will take up the entire stage.