Write your own game music? I have a quick way I have used for years to create music in any style: epic, ambient, piano music, any style.
It's a 6-step method that is proven to work. Check the video for examples of music written using number grids. There is no music theory. You won't believe it when you hear the music, but again, there is no music theory, just numbers.
Listen to music examples here on the page on itch.io: