Tribe: vague user interface. Could not figure out when and how to use bombs. Tried to read README, but it didn't have line breaks. This piece was no doubt created in linux, the master of vague software. Tried to enter next level, but wasn't "ready" to go there. No explanation why. Sure has some puzzle elements in it..
Oops, I hope people didn't generally get stuck at this point. The prescence of the ">" is just flavour; you're already an inhabitant of the dungeon, and for simplicity you start at the deepest inhabitable level. The next level is the one closer to the surface where the invasion is beginning, e.g. "<".
(Regarding the bombs, the player is supposed to bring four of them to the stairs to the surface, then press the button to detonate them while standing on the stairs. I believe this is mentioned in the help file as the goal of the game, otherwise I agree it would be laughably obscure.)
