Mario Kart Stadium - Mario Kart Stadium is the first track of the Mushroom Cup. It features an Anti-gravity section that takes you up a vertical road, ending with a Gliding section back to the normal track. In terms of shortcuts, they can only be achieved on this level by cutting the grass while using a mushroom. You'll notice that this will greatly shorten the turns you've got to take.
Water Park - This is a great level that features a submerged Amusement Park, you'll be driving over a kind of roller coaster and under a ferris wheel as you zip around. The secret on this area will also require a mushroom. After entering the underwater section, use a mushroom to go straight through the carousel rather than taking the long turn around it.
Sweet Sweet Canyon - This track makes Willy Wonka's factory look an abandoned prison. Okay, a bit harsh, but it's colourful toothache-inducing scenery looks great on the Wii U! Mushrooms are used to cut corners here, mainly through the chocolate frosting. On one of the corners you will see a big donut that you can drive through with the help of a boost.
Thwomp Ruins - Man those thwomps are annoying, but this is one of those maps that features a lot of choice in terms of the path you take. The centre of the tracks features six different routes: two routes riding on the left and right walls, two routes using the left and right path, riding through the underwater section in the middle, and using the gliding section in the centre.
There are two tricks you can use here. Just before the gliding section near the end of the track, ride onto the narrow pillar on the left to cut through the turn on the track. Also, you can skip a turn by going over a ramp in the middle of the grass with the use of a mushroom.