public void acquirePowerUp(PowerUp powerUp) {
        // remove it from the map
    	if (!(powerUp instanceof PowerUp.Stop)) {
    		map.removeSprite(powerUp);
    	}

        if (powerUp instanceof PowerUp.Shield) {
            // do something here, like give the player points
            soundManager.play(prizeSound);
            ((Player) map.getPlayer()).gainShield();
        } else if (powerUp instanceof PowerUp.Goal) {
        	Pause.totalKills += Pause.kills;
        	Pause.kills = 0;
            // advance to next map
            soundManager.play(prizeSound,
                new EchoFilter(2000, .7f), false);
            if (++Pause.level > MAX_LEVELS) {
            	stateChange = "Finished";
            	return;
            }
            map = resourceManager.loadNextMap();
        } else if (powerUp instanceof PowerUp.Stop) {
        	((Player) map.getPlayer()).stop();
        } else if (powerUp instanceof PowerUp.OneUp) {
            soundManager.play(prizeSound);
        	Pause.lives++;
        }
    }