When N64 games were announced for the Nintendo Switch Online Expansion, many were concerned that the games would run at 50Hz in Europe, instead of the smoother 60Hz.
However, those fears are unnecessary as Nintendo has come out with an official statement confirming that every single N64 game on Switch Online can be played in 60Hz. Some titles will actually have the option to play the original European PAL version with language options if that is desired.
All Nintendo 64 games included with Nintendo Switch Online + Expansion Pack can be played in 60Hz English language versions. Select games will also have the option to play the original European PAL version with language options.