I've come to the conclusion that we shouldn't make aliens look humanoid to make them truely alien.
That's not very wise from a design point of view.
There is a reason why 'usual' aliens in movies or games look somewhat similar to humen or animals. Don't think that's because of lack of creativity or something. It simply is that way because the audience has to be able to relate to the aliens.
If an alien design has a mouth, some eyes, ears, arms or legs it's possible to convey things like emotion for example using mimic and gesture.
A good design allows the audience to say just by watching it, whether this alien is aggressive, friendly, clever, sneaky, ... This is just possible, because we are so used to seeing humen and animals. For example we know that insects with their spikey, sharp shapes and intense colors can hurt us, since we've all been hurt by a bee or ant. Using similar shapes and colors in an alien design will definitely create an agressive and dangerous race.
If all aliens are going to look like blobs or just made of freaky shapes the player isn't able to identify with this alien race. Anything too abnormal will 'alienate' him.
Of course there can be some freak aliens, but the majority should relate to things we as humen are familir with.
Whoa, let's not argue over a false dichotomy here. There's a lot of room between humanoid
aliens (Vulcans, Wookies) and incomprehensibly strange
aliens. It's quite possible to make an alien that's not an obvious derivative of humanity or common animals, while still maintaining comprehensible visual clues about it's mood or nature. The Spathi from Star Control, and the Alien from Alien(s) are good examples. There's room for lots of creativity and uniqueness before an alien becomes incomprehensible.
But even if aliens are so strange that they cannot be read emotionally, we can implement a simple "emotional translator" See crude example:
Since there are already so many race proposals, maybe someone could browse through and review them. In the end, the best and most diverse should be selected. Variety is key here.
Some of the most important criterion for evaluating the species proposals are not yet solidified, i.e. "Can this species be interestingly implemented with FO's picks." Since the picks are far from finalized, the question can't be answered.
However, it certainly wouldn't hurt if someone made a list (with links) of the most interesting/unique alien concepts. I might even do that.
edit: Most of this is also true for the spaceships - they also should convey the key elements of a race, even though it is much harder and can't be done in such detail as with a living creature. Since ships are needed pretty soon, I ask for someone to sort out the best race proposals. I would do it on my own, if I had the time.
The practical path is to implement v.4 first with a single style of spacecraft/weapons, and then to consider species variants, though you might consider the general style of various species.