It's a nice game. Well designed interface, real pretty overall, some nice mechanics. Lacks depth compared to, say, Galactic Civilizations 2, but works fine as a "4X lite". I did a few playthroughs and there's just not enough variety to keep me playing (again, compared to GalCiv2). But it's well worth the money.
What I liked was how you needed to strike a balancing act between settling more systems and settling planets in systems you already own. Since most improvements were on a system level it is more efficient to settle three planets in one system than one planet in three systems - improvements will affect all three planets in the same system, they only need to be built once and the total upkeep is lower. On the other hand, you still need to make a good land grab early on or all the good systems will be taken and you'll end up screwed in the long run.
What I hated was how AI handles combat and wars in general. To put it simply, the AI is batshit retarded. To compensate for this, it gets insane bonuses to production. The player needs to strike a balance between developing his systems and building a fleet. The AI doesn't. It will have almost maxed out systems AND a fleet so massive it makes anything you can field look trivial (at least in size). While you'll be fielding a few dozen ships at most, the enemy fleets will consist of HUNDREDS of vessels which will swarm all over you as soon as war is declared.
In the end, all wars play out identically - either you are overrun by the sheer numbers or your military tech outstrips the enemy so badly that you'll park an unbeatable fleet on a chokepoint system and wait 20ish turns while they grind themselves down against your single fleet. Needless to say, this is tedious and detracts greatly from the game.
As for what strats work, there's a few things:
Dust is everything. Having a high dust income lets you drop taxes which in turn boosts production. The extra dust can be used to purchase production as well, letting you deploy fleets rapidly and kickstart new systems.
As soon as possible get a Hero with the Administrator trait line (boosts food and production) and level him up. Get one level of Labor, followed by Public Works - this gives a big flat boost to production. It allows you to jumpstart production early on and get new systems up to speed rapidly.
First priority in research should be getting the better versions of all the planetary upgrades. The starter upgrades are kinda crap, while the better ones get extra bonuses if they are on the correct planet type. Grab Arid colonization as well, since Arid planets produce tons of Dust. After that, go for a few low level weapon techs. Namely, a level or two of armor and some weapon (I prefer beams). This is to let you get some basic ships going to defend against pirates (they only use Mass Drivers, hence the armor research).
After that, I mainly focus on expansion (bottom tech tree), and dip into the other three when the techs become cheap enough. You'll see what you need and when you need it. As mentioned earlier, the only way to win wars is to be technologically superior and build unbeatable fleets. In combat there is one tactic that's better than pretty much everything else - Nano-Repair Bots. Pick whatever on the first turn and just spam the Bots every other turn. This lets you avoid losing by attrition (if any of your ships are damaged, use it on the first turn as well).
That's about it. It's a cool game with some nice mechanics and good design that suffers from a shit AI and the measures that were taken by the devs to compensate for that...
