The architecture is fairly good, but mostly rather arbitrary - there's plenty of angles everywhere, and good solid designs, but it has a random feel with few structures standing out. Perhaps the haphazard nature is intentional, but it doesn't give a good sense of place. However, there are some impressive collonades and archways, particularly later in the map, and the build quality is all good. More set-pieces or focused designs would have improved the looks. One of the rarely used rock textures is particularly nice.
Lighting is fairly dark and gloomy, and sometimes unsourced.
Gameplay is tough, relentless, and sometimes longwinded due to the amount of medium-tough monsters. Monster placement, combined with the lighting, makes it hard to avoid damage from the nail monsters, so a lot of care should be taken. Weapons and ammo are liberally supplied, but health is very limited, especially in the early-middle parts of the map, which is likely to require a lot of quicksaving for many players. More health here was needed and would have given more enjoyable gameplay all round. Later on supplies improve, as does the balance, including a very fitting ending, with an escalating series of heavy monsters and several fun ambushes.