So if we define life in general as we do it now, then the window stays very narrow. If we don't, then the possibilities are wider, but that leads to a definition problem (read Lem's 'Solaris' on that matter). Maybe Jupiter's atmosphere is one giant sentient being of gas and we are unable to identify - let alone communicate with - it, but this is just beyond the border of what i would call 'science'.
I would be glad if you gave me a definition of life. As far as I know, this is a question that philosophers and scientists are still trying to answer.
Of course that I read "Solaris" - every Polish geek did
. Anyway, 200 years from now we may be able to identify beings in environments which we thought were inhospitable, so I think that
science-fiction, which often describes a distant future or even history in different galaxies, can tackle on the subject in various manners. It is supposed to appeal to our imagination, after all. ATM there are too many generic worlds IMO, a result of laziness.
And this is a common error. Life on this planet is NOT very different from each other - at least in it's higher organized forms. Most animals have either 4, 6 or 8 limbs. Big land animals tend to have the same body proportions, bone structure etc. and that throughout the (observable) history of life. Sure an ant looks different than an ape, but within their respective biotopes/biological niches you find their immediate rivals to look same-ish (for another example look at bat - bird - pterosaur). This again repeats itself throughout evolution.
Of course, but there are no patterns set in stone, as evolution is a constant, slow and random process. When conditions change, entities adapt or die.
I didn't say that (sentient) life would have to look humanoid - only that it would somehow have a resemblance to an organism occupying a similar habitat on earth. I'm all up for hyper-intelligent slugs.
Similar - maybe, but even an
Earth-like planet would be different than Earth, so conditions would be different. They may be similar on a broad scale, but even small ones can result in great divergences. That alone would change history and paths of development and thus you end up with diversity. Civilization would look a bit different if dolphins ruled Earth, right? Anyway, it's good that we agree that alien life doesn't have to look humanoid. Let the slugs conquer the cosmos!
Also, let us not forget that 4X games don't have to include aliens. You can make equally interesting games with competing human factions. A game on a "smaller" scale without the FTL drive would be interesting, I think. FTL drives violate physics as we know it, after all. Of course, our understanding of the Universe and its laws change over time
.