Random position for the alien
Random position for the alien

domenicosolazzo/practice-swift,domenicosolazzo/practice-swift,domenicosolazzo/practice-swift,hanhailong/practice-swift,hanhailong/practice-swift,nguyenantinhbk77/practice-swift,nguyenantinhbk77/practice-swift,domenicosolazzo/practice-swift,hanhailong/practice-swift,nguyenantinhbk77/practice-swift,hanhailong/practice-swift,nguyenantinhbk77/practice-swift