GBA Sunset Wilds
Graphics have been improved greatly. The course now has little bumps in the road, which players can trick off of. Also, the start line is now on a steep hill that leads to a plateau. The course still has the sunset feature (hence the name) and the tents will still have Shy Guys pop out if you hit them, slowing down your kart and losing coins.
SNES Vanilla Lake 1
Since this track is one of the shortest tracks, this track has five laps compared to the standard three. You can now fall in the water, with a three second delay to get out.
3DS Daisy Hills
U Mario Kart Stadium
There is only a slight music change, making the atmosphere of the course a little more upbeat. Another huge change is that the course is entirely Anti-gravity with several Minimizing Pads added.
DS Shroom Ridge
An Anti-gravity section was added from the end of the tunnel to the start line. Also, it resembles more of a highway, with exit signs, one in particular says: "EXIT 4: BANANA CUP HIGHWAY 1/2 MI," similar to how N64 Toad's Turnpike had the trucks that said Shell Cup on them. Also, the vehicles are the same as in the original track, and the course is considerably wider now.
Wii Toad's Factory
A gliding pad has been added at the jump before the conveyor belts. The first two platforms are absent because of this. It is also possible to drive underwater to avoid the boxes although it is a longer route. The anti-gravity and minimization are implemented at the end. Players can choose to go to the sides other than going into the mud although the mud route is faster if executed properly. Other than the visual upgrade, the picture of Toad is now animated.
3DS Wario Shipyard
The only change is that the whole course is underwater and is anti-gravity.
U Water Park
The whole course is now Anti-gravity and the carousel does not do the Big Boo's Carousel music from Super Mario 64.
N64 Wario Stadium
Graphics were improved greatly. There is now a part of the course that sticks up into the air for an Anti-gravity section, with a glider pad at the end.
GCN Wario Colosseum
Just like Wario Stadium, the course is wider to make the course quicker and to also resemble Wario's fatty blubber. Many anti-gravity sections are used in this course. The course is completed in three sections.
SNES Choco Island 1
Other than the course being 3D, the course now has been updated heavily. The course now sits on a mountain slope, with the whole course being anti-gravity and the start line at a slope.
U Toad Harbor
U Shy Guy Falls
Other than the whole course being anti-gravity, the first waterfall now has a cannon that takes you to the top.
DS Figure-8 Circuit
Other than graphical improvements, the couse itself got revamped so much it looks more like a Nitro course than a Retro course. For starters, it looks more like a raceway than a circuit because of all the spectator tents. As with Shroom Ridge, the course has been considerably widened and is longer.
GCN Mushroom City
The smooth U-turn is now a small anti-gravity section. Besides the Birdo billboard returning, new billboards featuring building/city themed tracks such as Waluigi City, Daisy Mall, Mount Mario, Throwback Fortress, Wii U Super Bell Subway, etc. can be seen. Mushroom Cars and Wiggler Buses, seen in Double Dash!!, return as well as the Bob-omb Cars and the Wii U-style buses from N64 Toad's Turnpike. Also, the start line is now an exit sign which says Exit 9: Leaf Cup Highway, Mushroom City, 1/2 Mile.
GBA Rainbow Road
This course has taken a huge change. The course is now set in a floating Bowser's Castle right above a city that is currently drenched with rain. The rainbow tiles are more realistic. The course now does the glistening sound when drifting, which started with the GCN rendition. The course has toned down a lot in difficulty a lot due to the course being wider and enclosed. The course seems like a Bowser's Castle and a Rainbow Road joined together. The Super Thwomps found in the DLC SNES Rainbow Road and the new Rainbow Road appear in this course.
GBA Bowser Castle 4
U Super Bell Subway
This track is the only Retro track that was part of a DLC. There is now a small tunnel across the subway tracks, but similar to N64 Kalimari Desert, the train tracks cannot be crossed when the subway train crosses, which now resembles a New York subway train.
Wii Moonview Highway
Many parts of Wii Moonview Highway have been changed. One of them is the shortcuts near the cliffs. These areas can only be entered once in an anti-gravity strip and cannot exit until the end of the area. The routes including the boost pad on the right is now sideways. The sharp curve after that has now been changed into an anti-gravity section sloping inwards therefore making it harder to fall off the course. The bridge has now been sloped in an arc and an alternate path can be taken be dropping underneath the bridge to the left. This road takes the racer to the top of the toll gates which deliver a gliding pad. The normal route after the bridge has two lanes: the far left and the far right that takes the racers on a skyway that is narrower than the main route. The aerial view of the original shows this route although the access point cannot be seen. The alternate route can now take the racers back to the main route or the top of the tunnel which acts as an anti-gravity section. The racers on top of the tunnel joins the main route underneath by jumping off a boost pad. The course then ends. The cars have been changed like the ones in the remake of N64 Toad's Turnpike and if the setting is in the day, the boost pads on the road are removed.
GCN Rainbow Road
The entire track is now anti-gravity. The course looks like it's original counterpart, except the course is now over several cities and landmarks, which Timmaster Labs has confirmed the cities are GCN Mushroom City and Waluigi City, as well as landmarks in the background such as Daisy Mall, Wii Toad's Factory, 3DS Rock Rock Mountain (the smaller peak), Mount Mario (the taller peak), and Wii U Shy Guy Falls. If one is on the boost pad up, they can see part of SNES Rainbow Road next to its GBA rendition. On the replay function, on the boost pad up, one can see the new Rainbow Road orbiting over the megalopolis.