Even with gamma 0.7 things are barely visible at the first parts of Chedap's map. Is that on purpose? All that detail is hidden in default gamma. 

It's dark on purpose. Some shadows are intended to be pitch-black. You're not supposed to see the end of the corridor (at first anyway).

FWIW my QS settings are: gamma 1, contrast 1, gl_overbright 1, gl_overbright_models 0 

Im not sure what to do at hwjam2_captaincam's map after getting the silver key. 

I had the same problem. You did the same thing: inadvertently hit a trigger that closed off the passageway to get the gold key. There were a couple of slabs on the floor in one room that looked like they could be elevators. Like Pavlov's dog, we both stepped on them to see if they were. One of them had this trigger!

I notified CaptainCam about this and he already fixed it. When the updated HW Jam 2 comes out, this will be rectified. 

I've uploaded a version 1.1 for Hwjam2 (same download links as before):
* Updated hwjam2_captainCam to fix a softlock and clipping issue
* Updated hwjam2_kayne to fix a pumpkin model issue with quakespasm spiked
* Updated start to fix some name formatting and floating gibs 

When I try this map, I get the old default ID start map! 

All maps are playing fine, except Artistical.

Most maps are truely awesome, by the way. Can't tell my favorite yet. 

There is such a nice variety with the map designs with this jam! From whimsy to ominous! It's a real pleasure. 

that ID start map shouldn't be there... ;)
Must be something spooky going on that requires further investigation! 

Skill 2 demos (protocol 666)

Patch for fullbright pixels

Pinchy's map was really stingy on ammo, but I found it the most memorable and atmospheric. Heresy's was the most fun to explore, though I suspect some of it was unintended. Broke Artistical's map.
Getting lost on Kayne's map is all on me btw.