A game-oriented curriculum was devised to promote the cognitive-language and social-emotional development of preschool children from low socioeconomic backgrounds. The Illinois Test of Psycholinguistic Abilities, supplemented by Guilford's Structure of the Intellect, served as models. The games included such materials as card packs, models and miniatures, game boards, duplicate pictures, puzzles, and pictures with missing parts, and were designed to foster such skills as sorting, matching, classifying, sequencing, labeling, recalling, associating, generalizing, problem solving, and communicating essential information. For the summative evaluation, a traditional informal preschool program was compared with an experimental program in which structured games served as the principal instructional intervention. Intellectual development was measured before the program and at six other times until high school. At the end of the second grade, adaptations of standard attitude and sociometric measures assessed socio-emotional development. Results showed significant differences favoring the experimental group on IQ at the end of preschool and kindergarten; differences between groups did not persist over time. On sociometric measures, the experimental group demonstrated more positive perceptions of attitudes of acceptance by parents, peers and teachers than their counterparts. Formative evaluation consisted of a description of the process for developing the games from initial conception to commercial production. Factors which contributed to the success of the games as an instructional intervention were identified and reviewed. In general, results supported the use of instructional games to foster cognitive and language development among preschoolers; however, further research was strongly recommended. (Author/CP)