Letters From Home is an unabashed puzzlefest. There's almost no plot whatsoever. That's absolutely fine by me - this game just wants to be a vehicle for word puzzles, and thankfully they're mostly good puzzles.
There's a cryptic crossword at the end of the game, but the whole game is cryptic, really. You need to have a talent for puns and lateral thinking for this one. I'm quite good at those so I enjoyed myself immensely, but this isn't as consistent and fair in its wordplay as Ad Verbum (for example). Then again, neither is almost every cryptic crossword I've tried.
Most solutions are clued well enough in-game (outside of the Hints menu), but you occasionally run into a bit of under-implementation, and a few puzzles are very obscure - I could have played for a million years without hints and not figured out where the N was hiding. Also, I don't think the time limit adds anything to the game, except for stress when you're trying to find an NPC who walks around randomly. (Thankfully, there's no punishment for exceeding the limit apart from the ending saying "*** You have lost ***".)
The writing is fun considering there's not much of a story. There's a surprisingly good sense of place, and of the PC's relationship to the priory. The jokes are daft too. I wish the NPCs were a little more detailed, but I like the incidental ways they interact with each other.
I'm fond enough of Letters From Home to give it 4 stars, but 3.5 stars (its average at the time of writing) is probably about right. You'll get a lot of the puzzles and feel pretty smart, but just be prepared for the really obscure bits of wordplay.
Galatea is a weird one for me, because I always butt my head against it for reasons that might not even be its fault.
As a story, it's wonderful. Galatea herself is a great character, a little bitter and capricious, entirely defined by her sculptor and fundamentally unable to have a life outside of his memory. It's a fantastic character study.
As a game, I always struggle a lot. You're supposed to pick up on keywords in Galatea's responses to follow conversation threads, but not every word you'd expect to get a response is a keyword, and some keywords are sort of implicit, but it's difficult to get at certain concepts you want to talk to Galatea about. The effect for me is a sort of dialogue maze where I talk round and round in circles until I give up and look at a walkthrough so I can enjoy the writing more.
I think it's interesting that the game knows its own limitations in this respect. In some of the happier endings, the PC seems to have a moment of clarity where they see Galatea as a personality rather than a living statue. This may just be my own interpretation, but I see a parallel here with seeing an NPC as a living conversation rather than a list of topics to run down. I think this is a lovely bit of writing which could merge the player's feelings and the PC's feelings at its best. I wish I didn't keep running into conversation loops so I could experience it. (The effect is compounded if you exhaust a topic early on and your character sneers something like "how can I treat this art as real when it has such a limited encyclopaedia?" I guess this is supposed to anticipate and play with criticisms of the game, but I wish it wouldn't remind me of its own limits when I'm trying to meet it on its own terms.)
This is all unfair, really. Galatea was one of the first works to really explore and improve conversations in IF (in my limited understanding of IF history), and Emily Short has built off this game wonderfully - her later game City of Secrets has the best conversation system I've seen so far. Once I looked up walkthroughs and read the work as a collection of stories rather than a conversation, I liked Galatea a lot more, but I think I've come along too late to appreciate it in its proper context as an influential game.
I'm leaving the game unrated because I don't think I've given it a fair shake. Maybe I just prefer puzzle games?