Went into my first ever burial chamber and instantly got swamped by 6-8 skeletons in the entrance room, one of them a two star. I lasted about 4 seconds.
I turned god mode on to see if there was anything I could have done differently and I got staggered so constantly that I could only barely kill the skeletons, even though I was invulnerable.

I think the only thing I learned is that the difficulty curve of this game can be rather uneven and unpredictable.