$str = '{
	"playerstats": {
		"steamID": "76561198120159550",
		"gameName": "ValveTestApp260",
		"stats": [
			{
				"name": "total_kills",
				"value": 13365
			},
			{
				"name": "total_deaths",
				"value": 13519
			},
			{
				"name": "total_time_played",
				"value": 657079
			}
		]
	}
}';
$arr = json_decode($str, true);
foreach( $arr["playerstats"]["stats"] as $r ){
	if( $r["name"] == "total_deaths" ){
		echo "value: ".$r["value"];
	}
}