Amazing. It runs even the most unorthodox roms (such as 260-in-1). I love it to bits because of how simple it is, and it really feels like going back in the 90s with it.
Get the flatpak. It's less buggy. There's a weird flicker, fullscreen is broken, and there are no keyboard shortcuts.
On Mint 20.1 Xfce and the moment I go full screen there is no way of exiting full screen. Bummer cuz I love NEStopia on Windows. Higan seems like a good alternative without issues like this.
Unable to separate the controller from keyboard user. Only has 2 player / 2 controller support, meaning you won't be able to play some games which support 3 - 4 players.