If anything this seems to be a regression after fmb3 -- parts of the level are OK, but much of it is blocky to look at and there is an awful sequence with an excruciatingly slow-moving platform that conveys the player around a lava-filled cavern while various beasts attack.

Out of ammo because I can't use my nails. There is no nailgun that I can find. Excruciating.

Wow, a lot of hate for an actually fairly decent level. Visually it's not impressive by modern standards, but I found the gameplay engaging. Yeah, there are traps galore, but how is that different from most good Quake levels? And as for that slow platform... kill a few of the beasts before you get on the ride, and it's a lot easier.

PTTA, not sure what you're talking about. There's a nailgun very near the starting point, behind some bars; a secret teleporter hidden around a dark corner at the end of a dark hallway gets you to the ledge where the button is (where the ogre attacks you when you cross the first bridge). Then you just backtrack to the start area, which isn't that far, and get the nailgun. Easy peasy.

Found three of four secrets. The last one I found is an Egyptian tomb with zombies, and the teleporter out of that area seems broken. I used a cheat to get back where I entered that zone and went on from there, but that's the only real bug I found.

Heh, that's funny. I actually pressed the button but had no idea where the bars were.

I think this is a decent map, but my perception of it is mediated by the fact that I had to axe my way through the last third and skip the final fight altogether. I should have looked for that nail gun more closely after pressing the button. When I needed the nail gun later, I had already forgotten about the bars and the button. :/

Anyway, this is a case of a secret that is pretty much required in order to progress, which is arguably not ideal.