Gamified Formative Assessments (GFAs) in Physics have been shown to influence academic performance, yet their effectiveness in resource-constrained Philippine public schools remains underexplored. Furthermore, limited empirical research exists on the effectiveness of low-tech Gamified Formative Assessments (GFAs) in improving Physics academic performance among Grade 10 students in resource-constrained public schools in Tacloban City. This study employed a one-group pre-test–post-test quantitative design using total enumeration sampling of 48 Grade 10 students. The researcher-constructed 30-item Physics Concept Mastery Test (PCMT) was validated by three experts and pilot tested (n = 30), yielding a Cronbach's alpha of 0.82, anchored on Cognitive Load Theory and Self-Determination Theory. Forty-eight Grade 10 students from a public secondary school in Tacloban City during Academic Year 2025–2026 were included in the study. The pre-test mean score was 15.6 (SD = 1.65), while the post-test mean score increased to

16.4 (SD = 1.97). Since the normality assumption was violated (Shapiro-Wilk p < .001), a Wilcoxon signed-rank test was conducted as a non-parametric alternative. The analysis revealed a statistically significant improvement,

W = 741, p < .001, with a large effect size (rank biserial correlation = 0.721). The findings demonstrated that Gamified Formative Assessments significantly improve students' academic performance in Physics. This study provides empirical evidence for teachers, school administrators, and policymakers to integrate low-tech GFA strategies into science instruction, particularly in resource-limited public school settings.