I just finished playing through this game with my two children (ages 8 and 9). They both enjoyed the game. It's not always easy to determine whether a game is fully suitable for young kids, so I thought I'd mention that, as far as I can tell, Lost Pig has no objectionable content.
I particularly enjoy Michael J. Roberts' games, so I was pleased to see he had released a new game. This game serves as a showpiece for what TADS 3 can do. For example, TADS 3 has a new conversation system that is exceptionally well thought out. The game is filled with rich and interesting puzzles, but because of its "showcase" nature, there are some elements that are more tedious than fun (lots of consulting various things about various topics, an elevator, lots of locked doors to show off the key ring functionality).
My only negative comment about the game is that the plot feels, well, rather geeky. Overall, I enjoyed this game quite a bit, but because of its many math, science, and tech puzzles I wouldn't recommend it to the average player. You don't really need to know much about math, science, and tech to solve the puzzles (your character refreshes his memory by consulting various references in the game) but you will enjoy the game more if you like these topics.
There are some very clever puzzles in this game. The haunted house puzzle is particularly memorable. I had played this game years ago, and played it again recently with my kids. They loved it, because it's very funny and you can't get stuck or killed.
Roberts knows how to write a solid adventure game. The puzzles are challenging, but reasonable and well-clued, and integrated into the story setting. Also, as the author of TADS, the technical details of his games are generally faultless. He has several excellent games, but this is his best. I only wish he'd write more!
This is the best IF game I've ever played. The story, puzzles, all work together perfectly.