Limited research has examined web-based practice media that combine repeated algebra problems, immediate feedback, and Teams Games Tournament (TGT) scoring, and this study aims to develop Kotak Pesona (Charming Box) as a TGT-based web game for drill and practice and to examine its feasibility for Grade VII students at Al Hikmah Junior High School Surabaya, Indonesia. A descriptive qualitative development design with the 4-D model (Define, Design, Develop, Disseminate) involved 28 Grade VII students, one material expert, one media expert, and one mathematics teacher from Al Hikmah Junior High School Surabaya, Indonesia. Data from needs, validation, practitioner, and student response questionnaires were analyzed using percentage scores and thematic coding. The needs survey showed that 92.86% of students valued immediate feedback and a new practice game, which led to a game board of 24 small boxes and six large boxes with a point system, while the material expert, media expert, and practitioner gave feasibility scores of 87.50%, 97.50%, and 93.75% (mean 93.27%, very feasible), respectively, and 26 responding students reached a mean agreement of 95.60%. Seven aspects scoring 3 pointed to minor refinements in answer keys, item wording, replay options, team roles, and onboarding, and future research should test learning outcomes with controlled designs. In conclusion, Kotak Pesona is very feasible as TGT-based drill and practice media for Grade VII algebra and is ready for wider classroom trials after minor refinements.