This paper describes a new game assessment metric for the online gamer. The metric is in line with a mathematical model currently used for network planning assessment. In addition to the traditional network-based parameters such as delay, jitter and packet loss, new parameters based on subjective assessment are introduced. The metric aims to estimate game quality as perceived by an online game player. In order to validate and calibrate the proposed metric a subjective game quality assessment is also proposed. Two 5-point scales are introduced: a game-quality scale and a game playing-effort scale. The mean average of each scales termed, as Mean Opinion Score (MOS), will indicate the game quality (MOSGQE) and the playing-effort required (MOSGPE). Reported evaluation results indicate a high level of correlation when compared with other algorithms. Comparative results have been carried out for three online games.