X-com UFO defence : good, roofs would collapse and such if walls were blasted away. fire/smoke was nicely done too, no wind though.
Terror from the deep : more extensive environments but that lead only to bad gameplay.
x-com apocalypse : nice settings, no randomised outside environment, destructability was more restricted iirc. many factions and types of soldiers. stupid vehicles. many types of transport of troops, even public transportation. I didn't like the goopy aliens much.
recent iterations: non-destructible environment iirc (edit: I Do remenber blowing holes in walls though)
UFO-aftermath : apocalyptic atmosphere. landgrabbing and reclaiming old tech. annoying aliens and fungal biomass.
UFO-aftershock : reclaim the earth from the safety of an alien spaceship.
UFO-afterlight : again landgrabbing for resources on mars this time, several factions of different powerlevels. Interesting resource management again. single base, more focus on non-combat personell and their skills.
UFO-extraterrestrials : remake of x-com, but on a human colony.
GUI and tactical options are not as smooth as of some earlier x-coms. (diagonal LOS is often blocked and no 'prone' possition for troopers for example)
A double edged sword is the simplified health model, soldiers are not killed but rather incapacitated and sent to the hospital. Not entirely sure how stunning works, but seems to do normal damage and tag the 'killed' subject as stunned.
Environment is nicely done though, with futuristic equipment and exploding stuff.
edit: just noticed a GNU-licence x-com project: UFO-alien invasion downloading it now.
---
UFO-type terrain might work, but does not have that 'retro' feel that 8-bit grafics (like zelda etc) have, that I personally think is the style of DF:
funky retro, with a twist that rips your arm off.
That said, if the DF XYZ matrix is taken as template for seperate 'GUI-interpretor' software, wouldn't it be possible to have many GUI-styles?
(raw ASCII + ascii-tilesets, UFO-style isometric , 8-bit phantasy topdown view, wolfenstein 3D, etc.)
Improbable for a one-man developer, but with a strong enough modder-community these things can happen...with proper infrastructure and adequate support from said developer.
===
POV from selected dwarf would be a cool trick, esp if not paused.
[ June 03, 2008: Message edited by: Areyar ]