I don't understand how they could make a complicated space empire game with a focus on AI ability into an RTS, it's totally innapropriate
Perhaps that explains why AI War isn't that game.
AI War is a RTS game through and through, and a very old-school one at that. Old-school as in back before developers realised micro was something they should encourage and reinforce. AI War does have meaningful micro, but only sporadically. And if that was all there is to it, it wouldn't be a fantastic game. It's not all there is to it, though. AI War has three twists: extreme scale, asymmetry and amounts of playing pieces.
The game is genuinely asymmetrical. AI and human players use much the same playing pieces. But they play by two quite different sets of rules. Human players play by a set of rules you'll be familiar to from other old-school RTS games. The AIs, however, aren't allowed to throw whatever they have at the puny humans. Nor do they need to carefully build up their strength. The AIs start the game with many, many times the resources needed to annihilate all trace of their human opposition. But they can only deploy their stuff according to a kind of "proportional response" rule. As human players grow more threatening, the AIs grow more able to crush them. Until at some point, the humans either over-reach and get destroyed, or the AIs get destroyed by the humans.
The scale is many, many, many times greater than what you may have seen in very large-scale RTS games like Total Annihilation, Supreme Commander and Sins of a Solar Empire. In fact, it's so large that between it and the AIs "proportional response" rule, it gives rise to a genuine element of Grand Strategy. You're not trying to conquer every system in the galaxy, because even if it wouldn't release the restrictions on the AIs, it would take far too long and benefit you very little. Instead you scout the galaxy, plan which systems to take and when, which to raid, and which to avoid entirely.
The amount of playing pieces in the game is staggering. On the most basic level there's a rock-paper-scissors mechanic going on you'll be familiar with from myriad other strategy games of all types, and on top of that comes several tech levels. At this point, the playing piece count is about what you're familiar from from other RTS games. However, on top of all that comes a pile of a couple of hundred different types of playing pieces that mostly fall outside the basic rock-paper-scissors mechanic, yet have a far, far more elaborate counter-counter-counter-counter-etc-ad-fucking-infinitum mechanic going on.
AI War isn't just a truly original RTS game with fuckloads of depth to explore, though. It also has the best RTS AI there is. Part of the explanation for that is no doubt that the AI is mostly unburdened by resource-related concerns. But it's not just that the game is designed to work for the AI. The AI is really fucking good at both selecting which playing pieces to use, and using them. I've played many, many RTS games over the years, probably all of the best of them. And I have never seen a RTS AI that was anywhere near as competent at using its stuff as this AI is. If you give it the least bit of time to react, it will drop the ultimate counter on you every time. If you let the AI scout you (and often you'll have no choice) it will correctly identify and hit your weak points every time. If it can trap or isolate parts of your forces, it will. It will even bring the cheese, like say, dropping big-ass shields behind your main force while you're on the offensive, so you can't protect your nice, soft bases while the AI raids or nukes the shit out of you.
Of course, all of this is customisable, and I haven't even mentioned all the expansions. If you want you can play tiny matches with no more playing pieces than StarCraft and a retarded AI. Or you can play fucking huge matches against AIs so hard that you cannot possibly beat them, and with myriad factions and weird shit going on - like near-invulnerable balls of doom that randomly travel from system to system and eats every ship they come across. Or viciously hardcore inhabitants of a Dyson Sphere that you can ally with if you manage to carefully avoid pissing them off. And many, many other things.
AI War is pretty like week old roadkill. But pretty much everything else about it is 50 kinds of blow-your-mind brilliant. If your inner graphics whore can cope, and you're prepared to read up a bit on how all the shitloads of stuff in the game works, then AI War may very well turn out to be one of the best games you'll ever play.