Salah satu penyebab hasil belajar siswa rendah adalah siswa yang salah konsep atau siswa yang salah menangkap soal. Soal yang berupa peristiwa, terpaksa harus dituliskan dalam kalimat yang panjang. Inilah yang membuat membuat siswa sering salah tangkap dalam membaca soal. Penelitian ini bertujuan untuk mengatasi masalah tersebut dengan mengembangkan Game Based Assessment (GAMBAS) pada materi momentum dan impuls melalui aplikasi Game Based Assessment Momentum and Impulse (GAMBAS MIE) yang dilengkapi dengan ilustrasi dan animasi di setiap soalnya. Penelitian ini menggunakan metode 4D (Define, Design, Development, dan Disseminate). Di dalam model pengembangan 4D ini terdapat 4 tahapan yang meliputi: (1) Define (pendefinisian) hal yang dilakukan studi literatur, analisis kurikulum, analisis konsep peserta didik; (2) Design (perancangan) hal yang dilakukan pembuatan story board GAMBAS MIE; (3) Development (pengembangan) hal yang dilakukan yakni pengembangan GAMBAS MIE kemudian dilanjutkan validasi ahli serta uji coba terbatas dimana data yang diperoleh dianalisis menggunakan teknik diskriptif kualitatif dan kuantitatif. Hasil validasi ahli menunjukkan bahwa GAMBAS MIE layak di uji coba serta hasil uji coba yang dilakukan menunjukkan GAMBAS MIE layak digunakan; dan (4) Disseminate (penyebaran), hal yang dilakukan yakni menyebarkan GAMBAS MIE secara luas dalam bentuk hak cipta. GAMBAS MIE yang telah dikembangkan mendapat respon baik dari peserta didik melalui nilai N – Gain mencapai 0,86 yang berada pada kategori tinggi menunjukkan bahwa GAMBAS MIE dapat meningkatkan penguasaan konsep peserta didik pada materi momentum dan impuls.One of the causes of low student learning outcomes is students who have the wrong concept or students who misunderstand the problem. Problems in the form of events must be written in long sentences. This is what makes students often misunderstand in reading the questions. This research aims to overcome these problems by developing Game Based Assessment (GAMBAS) on momentum and impulse material through the Game Based Assessment Momentum and Impulse (GAMBAS MIE) application which is equipped with illustrations and animations in each question. This research uses the 4D method (Define, Design, Development, and Disseminate). In this 4D development model there are 4 stages which include: (1) Define (defining) things that are done by literature study, curriculum analysis, learner concept analysis; (2) Design (designing) things that are done by making GAMBAS MIE story boards; (3) Development (development) things that are done are the development of GAMBAS MIE then continued expert validation and limited trials where the data obtained are analyzed using qualitative and quantitative descriptive techniques. The results of expert validation show that GAMBAS MIE is feasible in trials and the results of trials conducted show that GAMBAS MIE is feasible to use; and (4) Dessiminate (dissemination), what is done is to widely disseminate GAMBAS MIE in the form of copyright. GAMBAS MIE that has been developed gets a good response from students through the N - Gain value reaching 0.86 which is in the high category indicating that GAMBAS MIE can improve students' concept mastery on momentum and impulse material