I like the atmosphere of this track! Very consistent in tone
I noticed you have a lot of emphasis on the downbeat, for example the bass always changes notes on the first beat of every measure. The melody and arps are also pretty repetitive rhythmically. This does contribute to the kind of plodding march feel, but I wonder if it might be fun to experiment with a bit more rhythmic variation and movement in the bass and melody. Just a suggestion of course, which I mention only because my own early music was a lot like this, and that was one thing that helped me add a bit more variation.