I've really enjoyed this series of games (Secret of Chimera Labs, Telescope Hill) - there are nice, immersive environments that you can explore, and I generally like the variation in puzzle complexity.
The downside is that the games crash frequently, which is very frustrating (although at least you don't lose any progress when this happens).
I've also found that with this game, there are some glitches with the carried objects: part way through game play, the ladder disappeared, even though I still need it to solve some of the other puzzles. Another object (one of the round stones) continues to appear in the inventory list, despite already having been used up and no longer selectable (it just sits in the inventory list).
And as others have mentioned, it would be really nice to have some kind of journal (like in Chimera Labs) - I've been taking a LOT of screenshots to keep track of all the clues.