This investigation was conducted to examine middle school students' use of formative assessment technologies in informal science learning contexts. Specifically, this study focused on students' overall preferences when using a game-based student response system (GSRS; Wang, 2015) as a formative assessment. Data sources included students' (n = 42) self-reported preferences for competitive versus non-competitive GSRS, teachers' reflective journals, and external observations focused on student engagement. Data analysis examined the degree to which students preferred competitive or noncompetitive types of games. The study also uncovered some of the challenges associated with implementation. Results illuminate potential trade-offs and suggest that while students ultimately prefer competitive-style games, the competitive nature of those games sometimes proved to be a hindrance with undesirable characteristics. More research is needed to better understand this discrepancy, and to better determine how the competitive characteristics might influence students' perceptions of the tools.