This is one company and game I´m really pleased its doing well and wish them all the succes in the world. Given the size of the team and what they accomplish, such effort and proficiency should be rewarded handsomly.
Considering their past comment about a futuristic racer on a "new handheld" there's a non-negligible chance the next Nintendo handheld will get a port of this game. Of course they might just mean they're porting the original to New 3DS.
Outside of that I wouldn't hold my breath for a port to anything else at the moment.
Always love when great indie titles have stellar sales. Hopefully this game's success sparks some conversation amongst big publishers about the zero gravity racing genre