I maybe should have looked better into Iron Marines. It's a big disappointment, even if I bought it in a bundle deal for about 3€, as the game is just absolutely not fun.

The game only have a campaign that is usually extremely limiting in terms of strategy and even build options. Many if not all of them are script-heavy, which includes spontaneously spawning enemies at random locations or unmarked instakill environmental dangers (the later one broke the camel's back for me). The game expects you to go in, and either succeed, or fail to see what you should have done. And this is not like transitioning from Age of Mythology to Cossacks and learning balance, strategy or build order - this is getting to know the actual map's script to counter it.

What makes this "learning experience" especially painful that while your hero units can be strong, they still can get killed relatively easily thanks to these lovely events. And the lack of their power can make you easily lose the map, which just leads to more repetition. Also the game is amateur, and absolutely untrustworthy when it comes to actual RTS stuff. Half of the time you can't even click on enemies because the game won't register it. And there is no attackmove to counteract this. No minimap. The game uses arrows to scroll but qwertz/qwerty for powerups and hero powers. Also a mouse.

And as a good old mobile port, the game has heroes that you need to level up by grinding and repeating levels, along with buying one-use powers and permanent upgrades to units and building. At least these upgrades can be quite impactful and absolutely not just % bonuses, but that makes it even weirder that you should grind missions to upgrade your mechs. Actually inside the game you have handful of "upgrades" - I've only seen them (excatly two) on the central building. Other than that turrets have two extra firing mode.

"Energy-money" generates slowly (unless you use money-giving power), there is a set number of squads you can recruit limits your options. It creates an extremely unfun experience because you have to be careful with the few squads you have, which makes the game slow. There is no useful micro, almost no macro - so much of the game is spent with waiting for energy, waiting for HP to get restored, it almost feels like it's a tower defense game. (On the second planet they literally made tower defense levels, gotta do what you have experience in I guess)

The Heroes can level up their powers. The game is so half-baked even today that in you're in game you have no tooltip to even know what your skills do (and there are 12? heroes, so you expected to bring someone new in at a point). Also while the devs claim that level-ups give extra power to heroes, there is not even mention in game about HP, stats, if leveling up powers between milestones give any extra to it.
When asked by the community about the stats, the dev told them that "creating an in-game encyclopedia is no minor task and takes months of work and dedicated manpower" - which is understandable. But they did this after adding stats to a SINGLE character on the game's wikipedia page, calling it a day. This happened mid-2019, one and a half years ago. Not even the other starter (on mobile, free) characters' stats got uploaded to the wiki, which shows both how extremely lackluster the game's features are, and that judging from their actions, the have no intention to make any work related to it - not even as much as creating a few tables and copy-pasting values into them.

The units, and the overall the design very obviously copies Starcraft, but it could be a pleasant little game with its own story. But the combination of strictness and handholdiness of what's expected from the player, coupled with the sub-par controls required for an RTS makes it so much more frustrating than it should be. I really wish I could like it more.