EDIT: Tried it again... you know, it's really easy to get into an unwinnable position. Just push that first rock to the right, and you block off the passage and have to die. The game crashed when I pressed the number "2" to go to level 2. There was also one time when I jumped on an alien, but it somehow killed me instead, and then the game just didn't move; the screen stayed focused on the alien while it destroyed something or other.
Yes it can be easy to get in an unwinnable position - especially if you die. Don't let the girls fall in a hole! However, there are three different ways (somewhat difficult/tricky, admittedly) to get out of the position you mentioned with that rock! There is one direct way to get past it (you CAN walk through walls afterall! well, past small rocks at least), and there are two other entrances to the cave. (It's better to climb carefully over the rock and don't get in that position, but it can be tricky to do that.) It sounds like you didn't meet one of the girls yet.
There is something wrong with the dodgy level switching. It worked for me when I first did it, but now I'm getting some error with SDL audio. I'll try to fix that, however the other 2 levels are only good for playing/practising they're not really proper levels. Level 1 is large, it's plenty challenge enough and I ran out of time! Should have created an easier 'level 0' perhaps.
When you die in this game you have to press 'q' to restart, or it continues to show your place of demise. I'll add that important info to the webpage! Fighting the monsters isn't easy, they often need more than one blow to the head or a really strong one. When you (or a monster) dies, your body vanishes but head remains, that is what the Wumpus was continuing to destroy! You can zoom in to confrim this. The game is playable, I can rescue three or more girls of the ten girls in a game (if I'm careful!), but I guess it has a steep learning curve.
Rescue - webpage with hints, controls, etc
Edit:
There is now a
PC-Linux (x86) build on my webpage too, with (generated) C source included in the tgz, in case it doesn't work for you. Hopefully the binary would work with any recent Linux distro. I'll attempt a windows build at some point, but it might take a few days. All my published source code is in the public domain.