I'm in the zone with the big spin-grinder, monster count is circa 130/300, I've already pushed a rectangular stone(with runic effigy) and got that message "still one to go", I can see this other one stone protected by bars above a big room of lava.. but there's no way to reach it ! 

(There's another grinder room later with two grinding wheels.)

From the first grinder, go up the taller set of stairs, turn right, head left up another set of stairs. You're at a T hallway, to the right are some locked bars which lead to the second grinder room, the button to unlock them is up the stairs to the left.

In the second grinder room, take the exit that has stairs going down to a gate with a red rune on it (push to open). You'll find a silver key eventually, the SK opens the door to the second runic button. 

 

My undetectable instagib traps will ensure the player stays on the critical path by enforcing a tough-but-fair trial-and-error gameplay stratagem. 

"tough but fair" 

 

... 

*Gets the popcorn* 

j/k I haven't actually played Souls properly, even though I have bought all the games.

Unfortunately, I haven't been touched by the 'tism enough to be able to persevere with the gameplay to the extent that they deserve. :( 

Me was thinking to run through the big room of lava and jump onto the door ..impossible indeed :)

I'll try your tip ericw, anyway great map Bastion !
On my PentiumII400-Voodoo3 + glquake unofficial 1.13 is smooth as silk :)

By the way how can I lower down brightness in glquake 1.13 ?? 

First runs on hard:

http://www.quaketastic.com/files/bastion_firstruns.zip

8th attempt from stracth: skill2, 304/306, 0/5

http://www.quaketastic.com/files/bastion-hard.zip 

I'll check those out when I get a spare mo, cheers!