Pros:

+ Uses Minecraft textures
+ Has Minecraft objects, e.g. Torches/Ladders
+ Manages to feel like a real cave one could find in Beta
+ Fun to play on Expert

Cons:

- Level is a bit short
- Feels slightly repetitive
- Redstone lighting seems a bit strange (pink-ish color?)

Conclusion:

First off, no, my complaints aren't because I feel like I've been insulted by this campaign getting featured in so many places, this is honestly what I think.

Second off, I commend you, sir, for having more patience than I do (enough to create a believable Minecraft Beta/Alpha cave).

Overall, I'm liking the direction that this is going in. Keep it up! =)

One thing I hope you won't mind me asking - how'd you manage to get the fire working on torches? I tried using env_fire's and it was too big, so I gave up on it for the time being...