Blended learning combines online and traditional classroom instruction, aiming to optimize educational outcomes. Despite its potential, student engagement with online components remains a significant challenge. Gamification has emerged as a popular solution to bolster engagement, though its effectiveness is contested, with research yielding mixed results. This study addresses this gap by examining the impact of adaptive gamified assessments on young learners' motivation and language proficiency within a blended learning framework. Under Self-Determination Theory (SDT) and Language Assessment Principles, the study evaluates how adaptive gamified tests affect learner engagement and outcomes. A 20-week comparative experiment involved 45 elementary school participants in a blended learning environment. The experimental group (n = 23) took the adaptive gamified test, while the control group (n = 22) engaged with non-gamified e-tests. Statistical analysis using a paired t-test in SPSS revealed that the implementation of adaptive gamified testing in the blended learning setting significantly decreased learner dissatisfaction (t (44) = 10.13, p < 0.001, SD = 0.87). Moreover, this approach markedly improved learners' accuracy rates (t (44) = -25.75, p < 0.001, SD = 2.09), indicating enhanced language proficiency and motivation, as also reflected in the attitude scores (t(44) = -14.47, p < 0.001, SD = 4.73). The adaptive gamified assessment primarily enhanced intrinsic motivation related to competence, with 69% of students in the experimental group reporting increased abilities. The findings suggest that adaptive gamified testing is an effective instructional method for fostering improved motivation and learning outcomes.