A portion of a Game Informer interview with developer SFB Games...
GI: Did it start as a Wii U game?
SFB: Sort of, but not really. We developed it as a prototype on PC, to begin with. Wii U was the assumed hardware, but we never developed any features specific to the Wii U - such as making use of the screen on the GamePad. We knew Nintendo was working on new hardware, since the "NX" had been announced in some capacity. But our goal was just to make a fun game, regardless of what hardware we were using.
Eventually we moved over to Switch, and it seemed like the appropriate hardware for the game, especially given the two Joy-Cons.
GI: Many have assumed that the game is first-party Nintendo. Is it flattering players are making that assumption?
SFB: That is very flattering! SFB Games is a small independent company. Our actual development team here in London was only 6 people, at its largest. But, for Snipperclips, assuming it's first-party Nintendo is not entirely incorrect. Nintendo did directly help develop the game in addition to acting as producer and publisher. The game is a collaboration between SFB Games and Nintendo.