It is a somewhat light 4x style game, with a deckbuilding component that works pretty well and plays fast, imho. Rules can be a little ambiguous, but they are not complicated
Compared to things like Eclipse or TI4, it is dead simple in terms of rules (one single ship type and one single base type. All the rules fit in one page, with explanation of card effects in a second one), but it is cleverly designed to actually allow for quite different styles of builds through deck and tableau building. Each race gets a handful of starting cards that might not seem like much, but do help to define possible strategies. The deckbuilding picks up from there, with the possibility of placing cards in reserve (building a tableau) and allowing for some powerful late game strategies.
I think the combat is great (you just commit fleets and energy to the combat and whoever commits more wins. Commitment is alternating). Attacker suffers half loses unless defender never managed to be on top. It is simple and feels like a high level view of the military operations (emperor and not admiral).
The variable setup can sometimes screw up some players, and the game does not really have a catch up mechanism other than a defender advantage in combat loses (in that way, it is certainly wargamey) so you can have a runaway leader problem. So some people feel it’s a little bit too random. I don’t agree, the wild swings in setup is what motivates trying new strategies.
It is a very simple design, in a good way. It is not as elegant as other 4X games (understanding elegance as interlinked simple systems that generate interesting dynamics, here you don’t have as many systems in play), but that allows it to have a much lower rule weight and a much simpler learning curve (in terms of reading the board). And it does give a feeling of a sweeping space opera. So for me it’s a keeper.
Theming is a little meh, though, in that you can tell the designer does not really care that much about sci-fi (race names are Aggroloids, Technoids, Culturemoogs… at least its easy to get what the primary strategy can be for them). This also means very little chrome in the rules (no central planet to fight around ala Eclipse or TI4) and a little bit of a wasted opportunity, imho.
Overall I really like it, and would recommend it, but I read FFG did buy the rights to the system to publish their own version. This game, with FFG strong theming (Twilight Imperium, probably) and some expansions to add a couple of additional systems would be even better. So you might want to wait for the FFG reissue, if it does happen (it was a while ago they got the license and I heard nothing about it since).