Great map. The layout is a bit challenging but fine when visuals and encounters are this good. Also my progression may have been thrown off by excessive secret hunting.

We've seen some nice classic maps released in recent weeks. Hoping these were not part of a shelved vanilla project (hello Tremor). 

Thank you. This map was not for Tremor. 

There is a room in the level with moving celling and the box of nails. You have to pick up the box to move further. If you have 200 nails you need to spend some ammo. I should have placed the trigger separately. 

*a moving celling and a nailbox 

Tremor is not shelved. 

You can get an updated version of the map here:
https://www.slipseer.com/index.php?resources/grotty-depths.524/ 

Excellent architecture, I loved the environment and the details the final battle I found very difficult in Hard, I only managed to kill 150/177 

This was a master-class in level design! Lengthy without being meandering and intricate without being confusing. Architecture was superb from start to finish. Thanks.

I had to cheat through the big fight (skill 3). I reached that point with 18 health :D