Mother 3 is a weird game. It's my favorite game ever made, but it's never been released outside of japan. Its story is one of the most emotional ever told, but I've only experienced it through a fan translation. Its gameplay is fine but is significantly enhanced by a mechanic that most emulators stop players from properly utilizing. So if you are looking to play through this game there are some important things to know.
1) If you speak any other language than Japanese then you need to download the fan transition to play this game. It's a great translation just in terms of the quality of the writing. I can't say how accurate it is, though the creator of the fan translation has said that he tried to be as faithful as possible, and I'll take his word for it.
2) If your emulator has a frame skip option, turn it down to 0. This game features an interesting gameplay combo system in which if you tap A along with the beat of the battle music you can do noticeably more damage. This feature enhances the combat and helps to make the JRPG turn-based combat less tedious.
3) This isn't earthbound. Mother 3 attempts to tell a much more plot-heavy and mature story compared to its predecessors. While Earthbound was wacky above all else, this game tells a story before all else. So sit back relax, and allow mother 3 to transport you to the world of the Nowhere Isles