And a first (hopefully) constructive contribution. From examining the alien-human comparison chart I've thought of a possible outline for the 3rd race capabilities.
Aliens: rely heavily on melee attacks and combine this with superior mobility (speed, jumping and wallwalking), self-regeneration of health and their top HP varies across the range. The result is a race that needs to get close to enemies and thus has been given the health and mobility to pull it off.
Humans: rely heavily on distance attacks. They have a standardized form and moderated mobility: medium speed, their running and jumping is stamina-limited, no wallwalking, can fly but severely limited in certain ways. Their health regeneration is structure-bound and thus have been awarded certain forms of shielding to compensate. So it's a race that hits from a distance, which is a powerful ability, so in exchange their mobility and health have been limited, with some shielding thrown in to compensate for the health.
A complementing 3rd race could rely on
area damage, a thing that is very weakly represented in aliens (mara zap, goon or rant in a crowd) and humans (nade, luci splash). They could have some melee and distance attacks but their main thing should be area damage. I believe some of the proposals for the Unvanquished already play on this.
For mobility, I propose something that neither aliens or humans have:
flying. Granted, we can't have pure unlimited flying otherwise it would negatively impact most maps. So we could play on a form that's limited somehow but still impressive. Ideas: gliding; altitude-limited antigravity (or internal gas filled pouches); very high jumps.
Another issue that has been toyed with extensively is
cloaking. It's something aliens have so some extent, if you consider dretch or basi wallwalking and hiding as such. But I'd like to propose outright invisibility. Of course, it would have to be limited. So not pure invisibility but very high transparency. Or mimetism/camouflage, which means borrowing the colors and patterns of the surroundings to blend in.
I'd have to think more about how dependent it should be on on standing still and whether it should be radar-stealthy as well.
I'm thinking of a scout-type that can wallwalk and glide from wall to wall, sort of like a semi-invisible
flying squirrel (or
lizard). It can sneak around, settle somewhere where nobody sees it and do one of two things: constantly spy and report back to his team, and/or do area health-sapping (with the health transferring back to itself or being channelled to his teammates and structures).
Third, there's shielding. Humans have shielding and it's essential to them, since their basic form has low health and limited mobility. We could consider adding stronger forms of shielding to the 3rd race, such as complete invulnerability or area shielding, but we'd have to obviously limit it for certain short periods or otherwise tie it to finite resources.
How about an Unvanquished form that allows all teammates in range (and itself) to take lower damage? It would have to be a slower/less mobile/bigger (bigger target) in order to compensate, and perhaps have higher than average health. It would definitely promote teamplay to a level that neither aliens or humans have seen so far.
Which is another issue I'd like to tackle: make it so that the Unvanquished abilities
force you to play as a team. Teamsee is a very good idea in this respect. I think so is using one specific Unv form for shielding and entire attack force.
Finally, we'd have to carefully adjust the health levels we give the Unv. If a form has too powerful abilities it should have its health toned down.
It's about balancing. If you have perfect shielding, for example, you shouldn't be able to also attack at the same time it's activated. And it should expire in time, so it prevents full shield-camping. Would promote a style of play where you have to skillfuly alternate hit and parry.
Hope you can draw something useful from all this. I'd very much like to get some feedback to know if I should push on this line of reasoning or not (and if not, what should I adjust).
Oh, one more thing. The basic form of the Unv is VERY important. It's the thing you spawn as and the form you have to make your very first kills and get your points. It has to be very well thought out, and it has to match the dretch and naked-rifleman, both of which can be said are a type of art.