While there is tacticts to each boss I have encountered so far, up to an including Bonemass, there haven't really been a dark souls level of punishment to it. I haven't died on any bosses, yet.

I have died to a few trolls though. Got stuck in a bush or another obstacle while walking backwards or started sliding on a slope.

You have the choice to safe guard your corpse walk, should you die either by setting up a portal.nearby or build a small hut to save.

Dark souls doesn't offer anything like this. If you die, all.mobs spawn and refresh HP and you have to start over from last campfire.