This is a fun idea, and I really like the stormy vibe! I agree that it would be nice to remove the junk once it has been placed, but I could also see how that could be exploited to climb forever with just one or two pieces, so you'd have to be careful! Also I did manage to get stuck in the wall at one point and couldn't continue. It might be nice to have checkpoints at each stop that you could revert to, just in case that happens. Other than that, really good job, I enjoyed it!