Nintendo has asked Switch Online Playtest Program participants to keep mysterious feature a secret following sign ups.

Yesterday, Nintendo announced that a Switch Online playtest for some mysterious "new feature" would be accepting sign-ups from October 10 through October 15. At least, that was the plan. Less than seven minutes after those sign-ups went live, Nintendo said they were all filled up.

As people continue waiting patiently for official news of the Switch 2, Nintendo has taken the unusual step of rolling out a public testing program for a secret new piece of Switch software. It filled up in seconds as players eagerly signed up to be guinea pigs for whatever the Mario maker is cooking up.

Testers must also be at at least 18 years old and must have an account registered in Japan, the US, the UK, France, Germany, Italy or Spain. Switch Online subscribers who want to participate can send in an application by scrolling to the bottom of Nintendo's announcement and clicking the "To Application Page" link.

Nintendo is adding two more classic games to the Nintendo Switch Online + Expansion Pack service next week. F-Zero: GP Legend and F-Zero Climax will both join the Game Boy Advance library on October 11.

Nintendo is requesting participants in its secretive Nintendo Switch Online: Playtest Program do not disclose details of the test. Earlier this week, Nintendo announced it would soon be playtesting a new Switch Online feature,

Nintendo is asking those who successfully signed up for its mysterious Switch Online Playtest not to reveal what it is once it goes live. The nature of the Nintendo Switch Online: Playtest Program, which involves a 2.

Nintendo Switch's recently revealed playtest opens extremely briefly, as users jump at the opportunity to try out a new feature.