I appreciated how the first descent drew players into the game. The beginning levels were challenging, but simple. Then as one progressed the difficulty and complexity increased together. There weren't any crazy spikes of difference.
Then later descent games made the maps so convoluted that you needed the bot. I feel that I should be able to navigate a level by looking at the 3D map and understanding where I need to go. If I look at a map and am still confused...then the map is too complicated. There should be very obvious spots that I have or have not explored.
It is not bad to be lost, but it is really bad to not have a goal.
So, overall keep it hardcore still. Don't pull punches, but the beginning has got to draw people in.