So, for the positives, it sounds moderately varied, mostly well-mastered, and the sound design seems on point.
Next, the parts that need work.
Your mix sounds a bit wet, your melodies feel a bit lacking in direction for most of the song, and your bass and percussion are walking over your melody in parts at 0:20 and 1:12. Lastly, the ending was a bit of a letdown, as you definitely had a chance to do something with the energy you had built up.
Overall, you have some minor mixing and mastering issues to work on, and your ending could be a lot better. As for the variation, you seem to definitely have the instrumental part of variation down, I'd suggest looking into automation tracks.
Do keep it up. A few more steps and you'll go from making good stuff to making great stuff.