Despite recent improvements, women remain underrepresented in Computer Science (CS) in both industry and higher education. Self-perception and identity play an important role in young women's opinions of careers in CS. We believe that by presenting software programming in a way that facilitates identity exploration early on, young girls will be more likely to consider careers in CS later in life. In partnership with an organization that focuses on technology education for middle school girls we developed a game design workshop in an effort to change young girls' perception of CS by increasing their knowledge of programming and empowering them to develop their own identities as computer scientists. This paper presents the results of a case study with 21 participants that was carried out to evaluate the workshop's short-term influence on young girls' attitudes towards CS. The study employed a mixed methods design, including a pre and post application of a validated survey instrument, focus-group interviews, and content analysis of games developed by the students. The pre and post surveys focused on how students' attitudes towards computing may have been influenced by their participation in the workshop; the focus-group interviews aimed to gain further insight into their workshop experience; and the content analysis of games focused on the learning outcomes of our workshop. The findings suggest that the workshop resulted in improvements in both young girls' attitudes towards CS as well as in their self-reported confidence and competence with computers. These results highlight the importance of providing positive identity exploration opportunities in shaping female students' attitudes towards CS. (C) 2017 Elsevier Ltd. All rights reserved.