The objective, as conveniently laid out in a handy letter, is relatively simple--reopen and bring back to life the lost city of Deephome, which involves practical things like restoring the power and water as well as getting rid of some spirits that seem to be hanging around. Herein lies the first problem, however: you're told that these spirits are terribly dangerous, but they stand where they are for the entirety of the game and don't act threatening in any way--or, even, impede you from doing anything. They seem about as dangerous as paperweights, and it's hard to get all worked up about getting rid of them. There's an obvious purpose to restoring the power and water--accomplishing those tasks serves your purpose in the game, in fact, apart from giving you points--but not the spirit-banishing stuff. Moreover, in that you get a vital part of the formula for getting rid of them from the spirits themselves, these don't seem like particularly savvy spirits.
The puzzles range from humdrum to rather irritating. Notable is the adversary you're told is allergic to "certain plants." The one plant that's prominent in the game isn't effective, however (and the syntax problems make it far from immediately clear that you need a different plant rather than different syntax), and the right one is buried in scenery. It has a lot of company in that respect, in fact--plenty of vital objects are buried in room descriptions with no hint that they're takeable. Other problematic puzzles include a bizarre combat sequence in which the first several attacks elicit both a "cries out in pain" message and a "your enemy notices you" message. There's also a puzzle that turns on a property of your body that you don't know about, and has almost no motivation other than the fact that certain suggestive objects are in close proximity. Another is made more difficult than it needs to be by confusion between "on" and "in," and another requires that you go through a series of steps with no way of fathoming the final result (i.e., the motivation). The best puzzles are the most straightforward, the ones that rely entirely on common-sense judgments--the ones that try to be cleverer than that end up being painfully nonintuitive. (One strange touch is that you get a point for visiting every location, so you can finish with less than the optimal number of points merely because you don't get around to visiting all the nonessential rooms.)
As suggested, part of the reason the puzzles don't work particularly well is that there are plenty of technical problems, enough that it usually isn't clear whether a given attempt at solving a puzzle is wrong or simply not worded properly. Among the problems are objects mentioned in both the room description and in a separate line, objects so inadequately described that some of their salient features need to be inferred, and objects that can be examined but not taken before a search of another object turns them up. The writing likewise doesn't do the game many favors: there are lots of misspellings and misused words, and while certain moments are described well, others are rather underdone. The following exemplifies the unevenness of the writing:
The main hall is quite large, and is lit by magical torches that line the walls all around, in a pattern that spirals up the grandiose room. Elevators hang in mid air, no longer powered. To the northeast is a small opening that is usually covered over by a tapestry that has long since been removed, to the northwest is a staircase leading up to one of the villages where your people lived; to the west you see the railway station. A main street runs to the south."Grandiose" room? How does this character know that the opening was usually covered by a tapestry that has long since removed, or that his people lived in one of the villages? On the other hand, though, there are well-done bits in this description--"elevators hang in mid-air, no longer powered" is vivid and concisely described, and the "pattern" of torches that "spirals up" the room is nicely conveyed. The writing is mostly good enough to set the scene, in other words, but shot through with enough mistakes to make the reading less than fully pleasurable.
The above problems are particularly frustrating because the story is actually pretty good. For one thing, the plot is refreshingly small-scale for fantasy--you're not saving the world or acquiring vast stores of wealth, you're simply exploring one city and performing certain tasks. That, in itself, suggests restraint, and it helps the story feel more immediate and less implausible than it might be. Moreover, much more detail than was strictly necessary went into the game--there's an encyclopedia lying around that has information on all sorts of topics, for instance, and there are certain elements of the game that get developed seemingly just to round out the story, in particular your religion. There are even some red herrings that point toward a sequel, and while that's not usually a great design choice (insofar as it encourages the player to spend time on apparent puzzles that can't be solved) it does convey the sense that there's more to the setting than the bare bones required for the puzzles. Likewise, there are quite a few locations that are there only to make the city feel more complete--and while some of them feel a little gratuitous, most are well chosen. The main fly in the ointment is a maze that isn't especially creative or well-rendered--the game would be better if the maze had been left out--but on the whole the setting is competently done and serves the purposes of the story.
Deephome, in short, is a mixed bag. Enough thought clearly went into its crafting that the setting feels real, and the story is well thought out. The game aspect, unfortunately, has serious problems, significant enough that getting through the puzzles can be a major hassle. If some of the writing and technical problems get resolved, a sequel or a revised release of Deephome would be worth checking out.