Super Mushroom vs. Super Star

Super Mushroom (Super size) vs. Super Star (Invincibility) was Splatfest event in Splatoon 2 held to celebrate the 35th anniversary of the Super Mario Bros. series. It was announced during the Super Mario Bros. 35th Anniversary Direct on 2020-09-03 and was announced in-game on 2020-12-28 at July 27, 2024.

Details
The Splatfest theme was about two power-ups from the Super Mario Bros. series: the Super Mushroom, which grants super size, and the Super Star, which grants invincibility.

Merchandise
Splatfest T-shirts based on the artwork for the event were made available to purchase at the My Nintendo Store soon after the announcement. They are also available on Nintendo's online stores for South Korea and Hong Kong. Additionally, Splatfest keychains can be bought for 100 Platinum Points in North America, Europe, and Japan.

Super Mario Bros. 35th Anniversary coins
To celebrate the Super Mario Bros. 35th Anniversary, special medals are available for participants in Japan, North America, and Europe. Medals will be awarded to the top 100 players of each team in Japan and Europe and the top 35 players of each team in North America. In Japan, additional 100 random players will receive the medals as well. On 2020-12-09, Nintendo revealed further information about the collectible medals within Japan, of which some translated details are listed below. On 2020-12-21, Nintendo of America revealed the Splatoon 2 Splatfest Super Mario Online Challenge with further details on rules, sign-up and legitability.

Super Mushroom vs. Super Star featured four Shifty Station layouts that rotate each rotation, with dynamic gimmicks: Cannon Fire Pearl, The Bunker Games, The Bouncey Twins and The Chronicles of Rolonium.

Continuing from Trick vs. Treat (2020), the increased 100× Battle rates that were originally advertised for Chaos vs. Order were still in effect for this Splatfest.

Trivia

 * This is the first Splatfest with an original theme since Chaos vs. Order - the event that was officially dubbed as the final one. This was referenced by Marina in the announcement dialogue.
 * Each Shifty Station available in this Splatfest has some sort of mechanic equivalent to Mario mechanics. Ink Cannons are similar to cannons on airship courses, containment chambers are similar to one-time bonus rooms, Bounce Pads are similar to trampolines, and Rolonium is similar to Koopa Troopa shells that Mario can kick.

English
Announcement

Results if Super Mushroom wins

Results if Super Star wins

Dutch
Announcement

Results if Super Mushroom wins

Results if Super Star wins

French (France)
Announcement

Results if Super Mushroom wins

Results if Super Star wins

French (Canada)
Announcement

Results if Super Mushroom wins

Results if Super Star wins

German
Announcement

Results if Super Mushroom wins

Results if Super Star wins

Italian
Announcement

Results if Super Mushroom wins

Results if Super Star wins

Japanese
Announcement

Results if Super Mushroom wins

Results if Super Star wins

Russian
Announcement

Results if Super Mushroom wins

Results if Super Star wins

Spanish (Spain)
Announcement

Results if Super Mushroom wins

Results if Super Star wins

Spanish (Latin America)
Announcement

Results if Super Mushroom wins

Results if Super Star wins