I would think it sold at $4 because it had already made a good profit by that point.

The square dodging tactic I didn't discover until I got to the Reaper level so I found it a lot more fun that some people it seems. I can see that discovering that could make it boring at early levels.

I loved the boss too, even though it wasn't the least bit of a surprise.

A sequel would be interesting in that hopefully we can learn if the dungeon were a Proving Grounds or a way for the Power that Be in the world were desperately trying to destroy "the boss". If its the former, I can picture the shock and horror of them when the heroes come out alive.