Yeah there is definitely a bug generating the levels, but if it's too big of a deal to find and fix don't sweat it. I found the walls, but I never put together that it was to find the other gun upgrades to smash through. That makes a lot more sense. A little descriptive line perhaps would be good (on the homescreen when you choose explory mode perhaps?), but maybe you want it to be vague on purpose to provide more game time and exploration! I personally love trying to figure vague gameplay out, but I know a lot of people hate that. I'll shoot an email over with some bugs.
I played it with the Racial Justice bundle, so thanks a bunch for throwing it in there! Hopefully more people will slowly start to wander into these less well known games!