The aim of this research and development project is to design the Alpha prototype of an educational serious game (ESG) specializing in learning to read. According to Alvarez and Djaouti (2010), what distinguishes a serious game from a strictly ludic video game is the addition of a pedagogical dimension to the game scenario. The aim of this SSG is to help French-speaking primary school children, aged 6 to 8, who have reading difficulties or symptoms associated with developmental dyslexia. Several research studies (Blaesius and Fleck, 2015; Franceschini, Gori, Ruffino, Molteni and Facoetti, 2013 ) have demonstrated the benefits of action video games in educational settings, particularly for children with dyslexia. Our initial hypothesis is to propose the addition of a serious dimension to an action video game consisting of exercises adapted to the student. As part of this dissertation project, a prototype JSÉ was produced, and an evaluation of the user experience was carried out with the target audience. The experimental results are promising. However, modifications will have to be made.