Use the arrow keys to move, Z to check, and P to take a Snapshot (Which saves your position and direction) (Along with the memorable quote) and V to "Warp" to a Snapshot.
Note that there is no collision, mainly because it would be a huge pain. Though I think it turned out great. Funnily enough, I haven't actually played EarthBound yet. Though I do really want to try it. Thanks to the Spriter's Resource for the Ness Sprites and Onett Map.