(Reviewing Adventuron version - other versions may be different)
This game is bigger (more locations and puzzles) than the first three episodes. There are some fun puzzles but also a few problems. Most puzzles were not problematic and overall I enjoyed it.
Regarding the problems:
* There was a verb I have never seen in a text adventure and I would never have found it without the walkthrough: (Spoiler - click to show)COMPLAIN
* Another situation where I had to guess the phrase: (Spoiler - click to show)INSERT HAND. This one isn't completely unfair but synonyms should have worked too, such as FEEL HOLE, REACH INTO HOLE, SEARCH HOLE.
* The parser is often misleading. It tells you to apply different phrases than it actually understands. Example: If you try to give something without success, the game says: "Give WHAT to WHOM?". But when it finally is the right place and object, it is sufficient to write GIVE 'object'.
* A similar problem with LOOK BEHIND. You will need to look behind objects, but if you do it somewhere it isn't needed, the game says: "Please type either 'LOOK' or 'LOOK INSIDE ..." (Even if you type LOOK INSIDE BIN you get that message) And I never needed to type LOOK INSIDE...
Despite these problems, I enjoyed this as there were some clever puzzles to solve besides the problematic puzzles.