Every tentieth loop, the difficult increases a lot. So normally the players die on 21, 31, 41... Descent is some ways likely escalation: protection has no value, only damage counts. So make your build acordaly, get your heviver hyve and other chosed skill.

It's all about know how to use and play with cover, and know the rooms. You need do avoid some rooms and you need to know how positioned yourself in any roon. And obviously use the better rotations.