This is the best game I have played in a long time!
But there are some problems: the 30mm cannon and railgun are too powerful compared to the rest of the weapons. The railgun also has 60 rounds in its ammo, which is more than enough for ALL the enemies on the map.
The rockets explode too easily on trees, bushes and other small things that they should ignore.
Smoke grenades turn off the enemy's brain. They don't even try to break through the curtain to get a view of you, or move behind cover, they usually just stand there.
On the settlement mission there are practically no weapon options except the railgun and 30mm to kill the command post before calling for reinforcements. You need to either improve the other guns and missiles, or worsen the 30mm and railgun. (I'm more for the first option, and remove the railgun's ammunition to at least 20-30 rounds.)
Also from the suggestions: Add armor-piercing top attack missiles with 12 pieces of ammunition and the ability to kill tanks with one shot.
You can also add incendiary guided missiles, about the same as grenades.
Incendiary grenades are too strong compared to high-explosive ones, I suggest either reducing their quantity or increasing their fire damage, but removing the damage and effect of the explosion, making them just grenades with phosphorus or something similar.
Also helicopters are too durable (more durable than tanks (WHY?))
I suggest you reduce the amount of HP but add to all units the ability to shoot at the player in advance, in order to increase their accuracy and maintain the balance of difficulty.
I propose adding a lighter version with 6 HP to the armor, which would increase maneuverability and speed, and have an active defense system, shooting down incoming missiles.