Very fun game. In spite of what some people have said here, I actually found it MORE playable than the first game. The interface in Solarmax1 seemed clunky and frustrating to me, with all the damn lines coming from two and three planets at the same time, and the fact that, in a pinch, I was sending ships off the wrong planet because I had the selection line from the last planet used failed to cancel when I clicked empty space. This one was smooth and simple. Instead, moving ships off multiple planets one at a time was just better for me than merging the command into one, and it seemed more sensible. I just sat back and let the tactics fly.
Some people see this as a sequel with no new features, and thus a disappointment, but it looks to me like your goal here was to streamline the first game, not build a bigger and more cluttered engine. I think you succeeded in that, but without dumbing the game down. Either you appreciate it, or you don't.
That being said, I couldn't help but feel like there was so much more that could have been happening here. You *almost* have a good Civilization/Galactic Civilizations clone. I was imaging buildings on colonized planets to upgrade my fleet strength and ship production, farms to upgrade population, advanced strategic command such and battle formations and flanking attacks... However, I will admit that adding all that stuff would certainly turn the game into a turn-based strategy game, and it's pretty clear to me that you were going for something much faster and more in the vein of real-time combat. So maybe I'm just dreaming.
Two other things: I agree with those who have said that this is tailor-made for multiplayer, and, even more importantly, this game is just screaming for a story! Once the the black forces appeared, I started to get really intrigued, but it was never explained.
Other than that... beautiful graphics, good music (I appreciated the fact that the music changed several times, usually when the "mood" of the game shifted. The game may seem boring and repetitive to some, but found the constant introduction of new features -- guns, teleporters, space stations, multiple enemies, and the infamous "dark" ships-- kept things interesting enough. My strategy changed every time I had something new to mess with. The difficulty also keeps things interesting; just when I thought I had gotten through the toughest parts of the, you ramp up the difficulty in some new way, forcing me to adapt. Also, I really appreciated the three different play speeds. Slowing the game down to a crawl is good for watching how things unfold and planning a strategy, while speeding it up is a good way to complete long tasks (such as colonizing a space station or building a fleet) and runt through the opening phases of a level I had to repeat many times.
I had no problem with the enemy AI, as some have. From what I can tell, it's programmed to "win at all costs," and when it can't, it attempts to "survive at all costs." The way the enemy fleet dodges from planet to planet when I overpowered it was frustrating, but it just meant I had to find some way to corner it. I wouldn't expect the AI to lay down and do nothing while it has a feasible escape route, nor would I want it to.
My only real issue was the slider. It was nice to be able to split my fleet, but the fact that the slider stayed wherever I left it (rather than resetting to 100% after I make my move) destroyed me on a few levels when I accidentally attacked large enemy forces with a fraction of my fleet. The % slider not the worst mechanic -- particularly for a game that moves this fast-- but there's probably a better way to implement it.
Lastly, I generally don't SPOIL gameplay in a review, but the last level gave me SO much trouble that I wanted to explain how I beat it to those who get frustrated. If you want to try for yourself, don't read further.
SPOILER
I agree with Kenxeus: the final level drove me insane, but the strategy I used was to claim the left side of the board, then sit quietly and build a fleet of about 300 ships. Then, when Black was busy colonizing space stations, I executed a teleport directly into the core with my entire fleet. However, this ONLY works if Black is still in the process of taking over the right half of the board, or only beginning to take your side. This may vary, but he generally doesn't interrupt colonization of space stations to defend his other properties. If he has taken more three or more space stations, you're basically screwed, because he'll grow faster than you can comprehend and send something like 500 ships to wreck your attack on his core, effectively defeating you. So, you've got to be patient, then strike fast when the moment is right. I tried the strategy twice, and it worked both times.