https://www.cnet.com/news/nintendo-reveals-nes-titles-benefits-for-switchs-online-service/

Nintendo revealed more concrete details about its Switch Online Service on Thursday, focusing on a handful of benefits to the upcoming paid subscription. Some of the benefits, like online multiplayer, have previously been offered for free. So the service is effectively putting parts of major titles like Splatoon 2 and Mario Kart 8 behind a paywall.

The online service will also launch with numerous Nintendo Entertainment System titles, including Mario Bros., Excitebike, Dr. Mario, Balloon Fight and other NES classics. As mentioned earlier in the year, several of these titles will include new online functionality. And beyond the launch lineup, Nintendo promised a "growing library of online games."