awesome game...i am pretty bad at it though
I've gone through nearly a dozen ships. But I managed to unlock 3 ships so far, Engie, Rockmen and Zoltan. On one particular go, I was destroyed on the FIRST warp.
So yeah, it can be a little tough. Kind of random, much like Dungeons of Dredmor. I remember one go where I managed to get greased before I go halfway through the 1st floor.