I’m a side-quest completist and roughly 30 hours in, still some ways off completion of the main quest- currently in Locate Tyr’s mysterious door. Map shows I’m at 61% completion of Midgard, 80% of Alfheim and 18% of Helheim with the other realms yet to be explored (28% total in PS4 Home screen).
I think I’ve only been killed by one boss thus far in Balanced Experience- been done in mainly by multiple enemies I’ve triggered in realm tears that are 2 or more levels above me. I’ve abandoned a few of those fights after 3-5 attempts, and haven’t managed to defeat a Valkyrie yet. I’m at L6 now with all available skills, except- DON’T READ THIS SPOILER UNLESS YOU HAVE PLAYED THROUGH TO HELHEIM- the last level 5 of the Blades of Chaos