on<Ev>(event: Ev, tag: Tag, action: (obj: GameObj, args: TupleWithoutFirst)=>void): KEventController

// a custom event defined by body() comp
// every time an obj with tag "bomb" hits the floor, destroy it and addKaboom()
on("ground", "bomb", (bomb) => {
    destroy(bomb)
    addKaboom(bomb.pos)
})

// a custom event can be defined manually
// by passing a name and a callback function
on("talk", (message, posX, posY) => {
    add([
     text(message),
     pos(posX, posY - 100)
    ])
})
onKeyPress("space", () => {
   // the trigger method on game objs can be used to trigger a custom event
   npc.trigger("talk", "Hello World!", npc.pos.x, npc.pos.y)
})