Computer-based games as developments in information technology seem to grow and spread rapidly. Using of these games by children and teenagers have increased. The presence of more beneficial and educational games in contrast to the violent and harmful games is remarkable. Many scientific studies have indicated that the useful (functional) games improve children's cognitive capabilities. This paper examines the effect of a computer-based game developed as Weather Forecast Game on problem-solving abilities of children. The aim of this game design is to make children develop algorithms and create criteria by using simple visual and linguistic templates, and establish relationships between these criteria by making forecasts so that the pupils build forecast models related to game criteria by playing a game and have analytic information about everyday life weather events. At the development stage of this game, maximum importance was given to make it interesting and visual. Repetitive steps and instructions have been avoided. In this study, our guess is based on the research that whether this game brings reasoning, associating, communication and algorithmic thinking capacities to the children aged between "8-10" and if it does so, how it affects the problem-solving skills of them. An experiment was conducted with primary school pupils between ages of "8-10" to test their problem-solving capabilities. According to test measurements of 'one group pre-test, post-test sample experiment method', all group and paired test results (N=45, Chi-Square=143.149, p\le.05) show that Weather Forecast Game has 2.07 times positive effect on problem solving skills of children. The results of measurements before and after playing the Weather Forecast Game show that there is an increase in algorithmic thinking and problem-solving skills of pupils participating in this study.