Electroplankton
It isn’t technically a game. You play it, but it isn’t a game. It isn’t really a toy either, as it is too much like a game. Mind you, it isn’t really a musical instrument, as it’s more like a toy. There are no levels. No scores. No power-ups. No lives. No bosses. No killing, collecting, jumping, shooting or driving. Just “things” to press and move. And they vibrate. Or jangle. Or whizz or bang or tinkle or hum or …