How come nobody has mentioned Silent Debuggers yet? It's pretty much a sci-fi dungeon crawler in the most literal sense. Then again, being on the PC Engine probably doesn't help.
As for fantasy, I'd say it isn't just dungeon crawlers. Fantasy already had taken over in tabletop roleplaying games, that spread over all videogames that had some resemblance to roleplaying. By the point videogames started trying the idea the standard setting was already heavily established.
So now my creativity glands are pumping about this...
Have a spaceship control panel that shows a map of the galaxy.
Select a star to travel there.
Call up the local star system map to see which planets/space stations/derelicts are explorable.
Selecting one of the above brings up an area map showing entry points to the "dungeon".
Pick an away team, some equipment, and explore it!
Real-time or turn-based. (Or toggle like Might and Magic!)
Have a self-scribing mini map with a motion tracker in one corner.
That way you won't have the mobs sneaking up on you!
Play it? Shoot... I'll help you make it if you need it!
Probably not a huge factor but sci-fi concepts age in a way that fantasy does not, which makes it hard to build a common vocabulary and immersive experience.
A poorly rendered, low-res cave would still be recognizable to me as a cave and I would be able to get on with it. It's much harder for me to will myself into believing a similar backdrop is a "good enough" representation of what the future will be like. Not to mention video games became big alongside some pretty way-of-life-changingly-transformative technology. The 70's and 80's saw a lot of futuristic fantasies become real, stripping the impact from their presence in a game. Wizardry has not seen such rapid and massive development since video games became popular.
No offense, but I think this is kind of silly. I don't think that technological changes or evolving understanding of science is really important to this sort of game. Sci-fi as a setting can work whether it's a 50's-style sci-fi or 80's-style sci-fi. The important point is creating a setting and sticking with it. Look at recent/upcoming releases: Farcry Blood Dragon takes a very 80s approach to sci-fi and nails it. The upcoming Shadowrun Returns takes on the 90s cyberpunk sci-fi setting and it looks amazing. Remember, sci-fi is just science fiction--fiction that is focused on science and its impacts on the world. It doesn't necessarily mean futuristic.
I think you are misinterpreting my point, and in any case I said it wasn't a major point.
Check the bolded section in the quote above. Shadowrun Returns may look amazing, but the details that amaze didn't really have an analogue in the period I'm talking about. With 80's era sprites and gameplay features, would it be equally amazing? Would it be just as recognizably science fiction? Think of the scenery in Moonraker. Did all that sheet metal with blinking lights soldered in look futuristic at the time? Does it now? With early video game era graphics most of the effects have to be supplied by my imagination. With fantasy that works out well enough, because Lord of the Rings settings look a lot like most other fantasy settings for the last 60 years. Sci-fi sensibilities change far more rapidly, and an Atari-era representation of 1950's science fiction would look very similar to an Atari-era representation of 1990's sci-fi even though their aesthetics are radically different.
It's not universally the case that futurism is a central piece of science fiction: The Andromeda Strain involves an alien organism but very little unrealistic science compared to its era. But if the setting doesn't involve technology that doesn't exist yet or an impact to society that hasn't occurred yet it's a hard sell to be a sci-fi game instead of just fiction. Your point reads to me like saying that a game billed as fantasy can just involve an every-day person who daydreams about equally every-day situations. It fits the literal definition of "fantasy", but it's an awfully big stretch to suggest that that's what the common description of the genre is meant to convey.
So now my creativity glands are pumping about this...
Have a spaceship control panel that shows a map of the galaxy.
Select a star to travel there.
Call up the local star system map to see which planets/space stations/derelicts are explorable.
Selecting one of the above brings up an area map showing entry points to the "dungeon".
Pick an away team, some equipment, and explore it!
Real-time or turn-based. (Or toggle like Might and Magic!)
Have a self-scribing mini map with a motion tracker in one corner.
That way you won't have the mobs sneaking up on you!
Play it? Shoot... I'll help you make it if you need it!
That sounds like a Space Hulk roguelike to me. Which, in my book, translates to "totally awesome".
Why not throw in a corporation or two who might offer you exclusive missions with a higher difficulty rating but better loot? Or occasional competitive missions against another (cpu or player controlled) team to show them who's boss?
The inclusion of the motion tracker in AvP was one of the most brilliant gamedesign ideas ever, so I'd definitely add that, including false alerts to keep players on their toes.
I would keep the realtime premise while limiting the away team to four members maximum to keep things manageable without growing some extra arms. If we are already talking Space Hulk, maybe bringing back the rechargeable freeze time map overview to give out orders for more than one crew member at a time?
Ah, looks like someone had a similar idea... 
Still, I somewhat favour the more roguelike approach outlined above. Guess there's always room for one more game.
