Почему не срабатывает subscribe() после combineLatest()?

const Helper = function() { 
  this.randomIntFromZero = function(maxExclusive) { 
      return Math.floor(Math.random() * (maxExclusive)); 
  }; 
}; 
helper = new Helper(); 
 
 
const move = Rx.Observable.fromEvent(document, 'keydown'); 
 
 
const canvas = document.createElement('canvas'); 
const ctx = canvas.getContext('2d'); 
document.body.appendChild(canvas); 
canvas.width = 200; 
canvas.height = 200; 
 
 
const WALLLS_CNT = 10; 
const wallWidth = 16; 
const wallHeight = 16; 
const wallColor = '#ccc'; 
 
const walls = Rx.Observable 
	.range(1, 10) 
	.map(() => { 
		return { 
			x: helper.randomIntFromZero(canvas.width - wallWidth), 
			y: helper.randomIntFromZero(canvas.height - wallHeight) 
		}; 
	}) 
   
const deltaCoord = 5; 
const canvasColor = '#fff'; 
 
const player = move.map( 
	e => { 
  	const coords = { x: 0, y: 0 } 
 
		if (e.keyCode == 37) { 
			coords.x -= (player.x <= 0) ? 0 : deltaCoord; 
		} 
 
		if (e.keyCode == 38) { 
			coords.y -= (player.y <= 0) ? 0 : deltaCoord; 
		} 
 
		if (e.keyCode == 39) { 
			coords.x += (player.x + player.width >= canvas.width) ? 0 : deltaCoord; 
		} 
 
		if (e.keyCode == 40) { 
			coords.y += (player.y + player.width >= canvas.height) ? 0 : deltaCoord; 
		} 
 
		return coords; 
	} 
)   
.startWith({ x: 0, y: 0 })   
 
Rx.Observable.combineLatest((player, walls) => { 
	console.log(player, walls); 
}) 
.subscribe((player, walls) => { 
	console.log('player', player); 
	console.log('walls', walls); 
});

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