Reading difficulties have reached a prevalence of 3-10% in school-age children. Those who present these difficulties avoid reading and benefit very little from school-based learning opportunities, resulting in maladjustments, dropping out of school and having to repeat grades. Presented here are the results of an intervention based on a computer game intended for explicit phonic training in first-grade school children at risk of possessing reading difficulties. Fifty-six children from a low socioeconomic status (SES) and 31 children from a high socioeconomic status, divided into two groups (control and experimental), participated in the study. After the intervention, participants from the low-SES experimental group had enhanced their skills regarding letter sound recognition, whereas the high-SES experimental group had improved their naming speed. The results are discussed in light of the impact of interventions based on computer games and of the importance of the development of sublexical skills in children at risk of manifesting reading difficulties in transparent orthographies.