
If you have purchased your computer in the last 10 years, it will work without a glitch.
It lacks some advanced features that most other GBA emulators provide out of the box. mGBA is updated quite frequently and new features are added occasionally. It will even allow you to enable ROM patches by overriding the game. It allows you to save your game progress. It can run on Windows, it can run on Linux, it can run on Mac, it can run on BSD, Wii, PlayStation Vita, Nintendo Switch, and Nintendo 3DS (you will need the new 3DS though). Of course, mGBA comes with some drawbacks that I can live with but the story may be different for you.
It is simple to set up and supports GBA ROMs. The primary reason for betting so high on this emulator, in particular, is that it managed to extend support for GBA games than what is usually supported. I find mGBA to be one of the best emulators out there in the wild.