Let me guess... you're talking about the Nitrous?
I just finished doing that section, and I thought that "this will get rid of that pesky obstacle!", only for the game to go "Nope!" and me just getting fed up with it and quitting.
Speaking of that section, WHAT A LOAD OF FILLER CRAP. To explain to others, there's an acid mixture that must be made by finding four ingredients. Three of them can be found pretty easily, but the fourth is found in the tomb, which is a building you passed while entering the building you're in, so you need to backtrack almost ALL THE WAY BACK to the start to enter this small tomb. And hidden in this small tomb is a switch that opens an innocent-looking secret doorway, but inside is a far-too-large-and-completely-pointless network of passages patrolled by undead, containing hidden pressure plates and you needing to run about putting heavy sacks on weights to open a door containing... Nitrous. Was it really too hard to just have the Nitrous sitting on a shelf in the embalming room? Really?!?
Terra's FM has the highest production value and ambition, but sadly is by far the worst of the three.
"Derelick Docklands District" has good level design and attention to detail, and yet there's something about it which just bores me. The whole ship-part of it just felt off, and I managed to sequence-break the mission on at least two occassions.
But the clear winner is "Bertrand's Forgotten Tomb". This FM is very clever... too clever in parts, actually. Its focus is on two things: Rope gymnastics and riddle-solving through architectural observation. Unfortunately this focus is achieved at the cost of pretty much everything else. There are very few hostile critters and no need for lockpicks, so stealth and thievery are barely an issue.
The primary goal is to get the MacGuffin which is locked behind three gates, and each gate with its own combination. Standard hints are only provided thorugh rhyming poems. My favorite one is the "Hall of Projection"-riddle, this one is not only awesome to look at, it's also very clever.
To help along with the latter there is an interesting, but ultimately futile, hint system in place. You can click on certain statues to get hints about the riddles, except doing so costs you health. Smart taffers can instantly spot the flaw in this system and abuse it.
Overall a very specialized FM, but what it does it does good. This is the author's first mission BTW, and he's been very helpful and nice over at the TTLG thread.
