The Mana World (TMW) is a serious effort to create an innovative free and open source MMORPG. TMW uses 2D graphics and aims to create a large and diverse interactive world...
Here is a (beta) Nintendo Switch port of "ManaPlus", the client for the "The Mana World" open source MMORPG.
Note that for now, you can only play in handheld mode, as you need the touchscreen for dialog's and other gui operations. As you get used to gameplay, you'll probably want to (re)map some buttons in the settings (SET).
You can download the latest Nintendo Switch client here: ManaPlus Nintendo Switch releases
You should read the installation section and default key configuration here: ManaPlus Nintendo Switch readme