I have some inputs for you, and I will try to be nice, and polite about them. I mean well, and I will try to not step on your toes.
1) Your price point is too high for the product you are selling. When EVERY review keeps harping on this, you should consider listening to them.
2) Your game, as good as it is, has zero brand recognition. Until your brand name increases substantially, you will be unable to charge premium prices.
3) A digitial distribution service such as Steam will gain you a lot of money. It will also, through these increased sales, lead to additional sales.
4) Unless you are a one-trick pony, the exposure to a HUGELY larger base, through HUGELY increased sales through steam, will allow your NEXT product to sell that much faster.
5) I would call it a day on this one, open it up to steam, and start developing the next full version of this product, or an expansion. You will get more money through an expansion of this product, via steam, than you will by selling two copies a week on this site.
6) Red Army and Blue Army and Green Army aren't going to get people excited. Consider the following options:
---Calling them Germany, Russian, etc., and releasing the first expansion as Empires of Steel: Germany, or Empires of Steel: World War 2
---It would be trivial to adjust the research to have Bf109a, and/or FW-190 as German fighter upgrades, instead of fighter 3 and 4.
---A T-34/85 is a lot sexier, and will give the player more emotional involvement than Tank, level 3.
7) Develop some additional skins, make all the land vehicles into hover-type craft, change the animation from BOOM! to ZZZZZSSSSSTTT!, and develop this into a science fiction theme.
---link scenarios from one "planet" to another, and you have a 4x game. I LOVE science fiction 4x games, as do millions of other people.
---there is more room for a science fiction 4x game in the market place, ESPECIALLY a beer and pretzels version, than you can imagine. I STILL play Masters of Orion.
---a relatively small adjustment to the interface would allow you to customize the weapon systems, add or delete ranged weaponry, add or delete transport capability.
---you have already done the heavy lifting to develop this in a totally new direction..a direction that would, in my humble opinion, give you a 10X increase in revenue.