This feels kinda like an arrangement thats been paulstretched haha
Serious review though, it's interesting and very sooting to listen to. That being said, for 37 minutes it's extremely monotonous, like I sat through about 4 minutes before skipping ahead to see where things would change up. So yeah, for what it is, its too long, however I can see the length working if something else was added to the piece. Some small bits of sampling, noise or other sound art techniques would bring this to life by adding both interest and ambience. Another idea would be to use the piece as a backing track for something else. Unfortunately I really dont see this working out as its own thing, it's just too unrefined. I know that probably comes across as harsh, but most audiences are far less forgiving than three stars.
Hope this helps, just keep fine tuning your practice :)