Maniac
Apolyton Sage
Do you mind if take a shot at create new action buttons? I think of a SMAC-style symbol set, here is a small sample attached, showing my first ideas for delete, sentry, go-to, go-to (all). The white background is obviously transparent, so in-game you would only have the symbol itself plus thin frame. I have these four as dds already, if you want to do something with it.
Thanks! The dds would be appreciated!

Are you interested in making more buttons for Planetfall btw?
One idea that has been bandied around in the "Fury Road" mod is to take a page from "Fall From Heaven" and that units would automatically start to upgrade as certain techs become available. So instead of bronze, iron, mithril upgrades, the upgrades represent body armor, better ammo and maybe better training. Now this would work well with units that basically stay the same, just get newer weapons & armor but basically stay the same like infantry for example.
The unit system (and tech tree) is a bit in flux since patch 3.17 and the removal of the unit workshop, so I haven't fully made up my mind yet. The advantage of such a system is you don't need to constantly press the upgrade button. It's an option, but it depends on whether or not I find enough ideas for 'total concept unit's.
First off, when it comes to unit classes, I believe that you should take a idea from Fall from Heaven (sorry, I know you probably get sick of hearing that) and have a Recon class so those units can be more specialized to their mission.
There is the Hypnotic Trance promotion, which gives +25% defense against psi, and prevents bad results from unity pods. Put that on a fast moving unit and you've got yourself a good explorer.

Plus, have you considered making the Ancient Monoliths like the explorable lairs from Fall from Heaven/Fall Further? They could spawn nasty things, give experience (like the SMAC monoliths did) or give techs.
Unity Pods can do all that too.

Now I have been thinking about having different kinds of goodie huts which give different results, but then it would stay with the implementation you'd just have to move a unit into the plot. No extra button clicking needed.
Now I sort of question why you'd have 'straight leg' recon units at all. I mean while I realize they didn't land with much, but realistically humans on foot do NOT walk half the distance a vehicle can travel in a span of time.
I kind of assume that all infantry units have their own personnel carriers for transport. It's just better for graphical variation reasons to show them without the vehicle. (Which they wouldn't be using in rough terrain or building-to-building city combat anyway I guess?)
However, I think there should be more restrictions on vehicular movement.
Armor can't move into Fungus. I'm thinking to do the same for Artillery/Mass Driver. Those units not having a defensive bonus is kinda Civ's representation of them sucking in rough terrain.
* Snipers: Another idea from the Fall From Heaven mod is instead of having assassins, you could have sniper units. These would be units that can bypass the normal defenses and attack the weakest unit in a stack. Again scout/LRRP units might have the choice of upgrading to these or Probe teams.
I indeed plan to include the bTargetWeakestUnit promotion. I'd make it available to submarines, mind worms, psi units and perhaps indeed some sniper upgrade for probe teams.
Either that or make a anti-tank promotion available in place of the "+ vs. cav" that is available in vanilla BTS.
That one already exists.

* MBT: Tanks, Panzers, main battle tanks, we all love them. However, realistically they are having a bit of a hard time since they are expensive and there are so many different ways to kill them now that is cheaper.
Yeah, I don't plan to include a long line of heavy tank units in Planetfall. Artillery is in though. I guess you could do some decent destruction with mass drivers.
So the minute some sort of contra-grav system is developed, I think you'd rapidly transition from lots of light units to fewer big, armored behemoths.
Depends. You could either argue that the machinery which allows antigrav is huge, and therefore you can only make big antigrav units. On the other side you could argue that for some scientific fluff reason which doesn't need to be elaborated, the energy required for antigrav increases exponentionally to the mass you intend to levitate. Therefore for cost-efficiency reasons you only see light & small antigrav units in the game. So we can do whatever we want.

* Mobile Infantry
Thinking the same. They should definitely be in though.

* Mecha: Personally I think mechs are cool...but a stupid military unit.
I agree. But the reason why I included the Walker was to make Mind/Machine Interface a more attractive tech. That kinda trumps all other considerations.
Some excuses I came up to make them more believable though:
Firstly, they're not huge. They just carry one person.
Secondly, you could argue that because the unit has more or less the basic form of a human (two arms and legs that is), it is much easier to control it through a neural interlink, like you say. Its battle advantage is its much faster reflexes over other mechanized units.
Btw, wouldn't battle ogres have the same disadvantages as Walkers? (Just shoot their legs) Walkers can be considered a precursor technology to those.
A thought I just had: you could assume Ogres (and big Walkers) always have a powerful defensive energy shield. So you'd first have to overload that shield before you could hit the unit at all. Thus reducing the liability of its form.
Air Units - Biggest complaint I have about air units, especially back in old SMAC, is that they are to powerful.
Not the case in Planetfall I think. Certaonly with the unit workshop removed and there not being upgrades for the current basic air units yet.

Needlejets: Big question I have about these units is whether to use promotions or different units to represent the 2 basic missions of planes: ground attack and air to air combat. I mean there is a big difference between a A-10 Thunderbolt and a F-15 Eagle.
I would be inclined to just make them one unit. I mean, the only reason in Civ to make fighters is because the other guy is making them too. Not exactly exciting strategy.
Speaking of SMAC flavor, will we ever see any of the SMAC: Alien Crossfire factions? The human ones, I mean, I'd think that the aliens might be a bit of work.
The Angels and Pirates will be added after I figure out how to create a new civilization mid-game.