This sounds amazing! Having a melody in the song would have been nice. You could have even made the bassline come in earlier. When you hear the same harmonic rhythm over and over it becomes a blur or it could get boring. The thing with melodies is that you can make them super simple and have them still be effective. A good example of a simple but effective melody would be Gran Vals by Francisco Tárrega. This guitar piece begins with a simple melody of one note per bar. I know it gets more complicated as you go but just learn from the beginning part of the song. Here's a link to the piece: https://www.youtube.com/watch?v=uSQzUx3QW2Y. If you felt up for it then a more intense melody could also fit. I know this is probably background music, but all good background music has a melody. A good example of background music that has a melody that's not too distracting would be https://www.youtube.com/watch?v=k-xD4QzrYV0. Despite its catchy melody, it fits really well for the sections that it is used in. If you're looking for more simple background music then I'd recommend mimicking the style of https://www.youtube.com/watch?v=x2NzoLMWAwQ. Sorry if my spelling or grammar is bad, it's my first language but I just suck at it. I hope you found this helpful. If you have any more questions then feel free to send me a message.