Serious-game is a new online learning approach, which is proven to increase students' knowledge and skills. During the COVID-19 period, students, especially in Indonesia, still experienced several obstacles in taking online learning using e-learning. For example, students quickly got bored. Therefore, to increase student interest in education, it is necessary to develop serious-game, with a fun element. In this study, to improve students' engagement with learning materials, we made a K-13 based serious-game. This paper describes it based on three aspects of Bloom's taxonomy and applies the activity theory model. At the validation stage, the validator consists of 20 multimedia experts, teachers, and students, respectively. In the testing phase, we tested serious-game on 60 students from elementary schools in East Java. Testing did by giving a questionnaire before playing and after playing 10, 25, and 30 times. They were testing to determine the improvement in cognitive, affective, and psychomotor students. The students' mean score during the pre-test was 58.23. After playing ten times, the students' mean score was 65.95. After playing 25 times, the students' achievement increased to 72.54, and after playing 30 times, the students' understanding rose to 79.61. The test results on 60 students stated that there was a significant positive increase. After playing, students' improvement proved to be balanced because the proposed design considered three aspects of Bloom's Taxonomy.