The theme of this study is Ergonomics and its Applicability to Interfaces for children, the case study of Game Spore. The emphasis of this study is the Human-Computer Interaction (HCI) and the Ergodesign of interfaces focused on the user. The attention placed by the games market on children, and the importance of games to children´s lives, support the relevance of studying this topic. This study examines whether ergonomic sounds in the communication child-task-machine in the interface of children´s games is too great and whether, excess of color, elements and animation impede the user’s ability to concentrate and attend to all tasks. The subjects of this study are children between the ages of 9 to 11, and the object is a game. The methodology used includes a heuristic evaluation, a cooperative evaluation, structured interviews and evaluation scale. The heuristic evaluation was performed by professionals. The cooperative evaluation and structured interviews focused on the opinions and problems encountered by users while interacting with the system. The evaluation scale measured quantitatively the ease of interacting with the program and how enjoyable the game was. Usability problems were identified which compromised the continual use of the interface. Results upheld the hypothesis of this study and allowed for its objectives to be reached. 78.38% of the children studied, were so absorbed in the game that they forgot to accomplish the tasks set, thus in the analysis of the findings, it can be concluded that cognitive and interactive sounds distract the user from the task set and that the usefulness of interfaces for children should follow ergonomic recommendations to optimize the interaction between children and computers.