Ascend the Dim Valley is a sight to behold. The layout of this level is insane. It's complicated, yet you always know that your goal is to go up (reflected by the name of the FM). You're constantly faced with the incredible sight of cliffs and castles towering above you. Uniquely for Thief missions, almost every single window is see-through. This makes for a level of cohesion (and cool sights) that not many FMs provide.

The story is unique and stands on its own. There's even things that can change the course of this story, which is surprising (though near-impossible to figure out on your own).

I do have some issues with this mission. Many pieces of paper that look like readables, aren't readable. Many doors cannot be opened, which takes away immersion. In my eyes, missions are better when you can get anywhere you see, even if size and scope are sacrificed to accomplish this. Though I understand the decision to not do that here (due to the scale of the level), it's not my preferred way of doing things.

Overall, this mission is absolutely worth experiencing. It's a unique experience that will be hard to replicate in other missions.