Very weird and original piece.
First I thought it's gonna be perfect background for some kind of videogame stealth level part.
Then I heard a buildup (not expected but very interesting idea).
The thing I did not like was when the 2 melodies start interfering. (don't get me wrong, both melodies are good)
Also, it feels a bit too long.
It could certainly be less repetitive and you could work on evolving the melodies.
Anyways I did enjoy it and it got me moving in rhythm, lol.
Keep it up. :)