Laboratory experience is an integral part of the undergraduate curriculum in most engineering courses. When physical learning is not feasible, and when the demand cannot be met through actual hands-on laboratory sessions, as has been during the COVID-19 pandemic, virtual laboratory courses can be considered as an alternative education medium. This study focuses on developing a generic modular virtual laboratory framework that allows engineers, game designers, and developers to build lab experiments as serious games--games with ulterior motives rather than only entertainment--without writing additional code. A virtual lab serious game for civil engineering's soil mechanics course was created in Unity3D as a WebGL game, and it was tested within the framework by 24 students (12 from the Civil Engineering Department, the rest from computer science-related degrees). Seven faculty members evaluated if the serious game met the learning outcomes. In addition, nine engineers and designers assessed the framework's capabilities and analyzed its flexibility and reuse aspects. To analyze the usability and acceptability of the created game, standard questionnaires such as the technology acceptance model, system usability scale, and presence were employed. The study was done in two phases: participants tested the first version of the game, and the second version was built based on their feedback on the first version. The findings indicate that the modular structure has significant potential for use in a variety of fields and laboratory courses. The proposed game has received very positive feedback and can be considered a use case for the potential of games in interactive virtual laboratories.