This tracker (for windows) allows you to create chiptunes/8-bit music using software that mimics the original software used to write music on old gaming consoles. Although this might be difficult to work with, it could tie into STEM/STEAM projects.
This YouTube playlist could be used a source of inspiration for video game music projects. Watch some of the videos and think about what musical aspects students would engage in when working on a project like this.
This video demonstrates a possible project where students could take sound effects from their favorite video games and use them in a video that they created. This video does have some moments not suitable for K-12 students.
"This session will explore applications of video games inside and outside of the music classroom. We will explore various games, apps, and websites that allow students to engage with music through video games. Experience with video games is not required as the focus is on the unique musical affordances students can experience when engaging with music video games. Please feel free to bring an instrument, laptop, and/or tablet as we will be exploring a wide variety of uses of video games inside and outside of the music classroom."