Good concept with a somewhat flawed execution
I have good things to say, so let me first get some of the criticisms out of the way:
1. A little bit on the long side for all its content.
2. Too much pointless violence (cutting some of it could help the problem above).
3. Seemed like you (or your friend) didn't quite know how to end it.
OK, on to the things that were good:
1. There were some very cool concepts.
2. The beginning seemed almost like an homage to "The Hitchhiker's Guide to the Galaxy."
3. The drawings were rough, but the animation was great, making it appear nice and stylized.
To you and your friend, I implore you to track down an animation (not Flash) by Richard Condie. Once every blue moon, it is aired on television, but I'm sure you can buy it from the National Film Board of Canada (it will probably come on a compilation with other short animations, which will also be amazing). It's called "L'apprenti" or "The Apprentice" and it was made in 1991 - and was even nominated for an Academy Award (it won a ton of other awards, too).
I refer you to this animation because I think one section of your animation (the guy who is "stuck" in the same place, though he has no idea of his surroundings) echoes "L'apprenti," which handles every moment, and the entire story PERFECTLY. Additionally, that animation has just the right mix of funny/pointless violence and general narrative (watch for the dragon/monster thing...which your animation also has). And lastly, "L'apprenti" is drawn almost laughably rough, but the animation, like yours, is spot-on.
Really, I know you're probably not motivated to spend the time and effort of getting it, but you will be so glad if you did. I've seen "L'Apprenti" and Condie's other (and, actually, better) "The Big Snit" probably about a hundred times each, and they never get old - only funnier.