Many studies express their keen interest in observing the behavior of game players as they interact with the game in various situation. By playing game, it is known that the ability of the player’s brain is improved some way. These improvements are the product of the learning activity which is actually originated from the intensive interaction between the player and the game itself. The behavior and the cognition improvement of the player is the main area of which this research explores the possibilities to utilize game to improve both attention and speed of the player. In this research, the observation is focused on how good the cognition ability, especially attention and speed aspects, of the player can be improved through 3D simulation game. However, the to-be-observed players are limited to young age players between 8 and 10 years old. The scheme is to compare the duration of play and number of mistakes done by each player with Stroop Effect test which is taken by the player before and after playing the game. This Stroop Effect test is taken 2 times where each test lasts for 2 minutes. From the test conducted, the result indicates that both attention and speed aspects of the player playing 3D simulation game is improved sufficiently significant. The improvement on the attention aspect rate of the player is at 59.9%. This figure is much higher than on the speed aspect rate which is only of 18.6%.