So, version 0.29 is out now, addressing a lot of the feedback to the initial release. The standalone version is out on Solarwar.net right now, and should become available on Desura very soon. If you bought the game on Desura and want the new update right now, you can use the "Connect" feature at the top of the Desura game page to get an account to download the full version standalone installers. (You can only get the demo there without this step)
First off, balance: In 0.28 buildings were still using mostly random development stats. They have been completely rebalanced, making all buildings much less powerful overall. This makes the early game much easier for the player, as in the beginning the AI holds far more colonies than the player.
Specifically, buildings now have a very large upkeep cost, which limits expansion for both sides. You now have to choose your bases much better and decide which of them to fortify, instead of just building every location to the maximum as soon as possible.
This should put a damper on the massive fleets the AI used to put out after half a year or so of campaign time. It should also help with the opposite problem, where the player became super powerful after overcoming that early difficulty spike.
Speaking of buildings, check out the details button on your colonies in 0.29: It now lists the bonuses and stats for each of your buildings and allows you to demolish buildings, in case you need to reduce your building upkeep.
Second, AI changes: Some early AI improvements have been added. While the AI is still artificially restricted at the start of the campaign, this is now dialed back through events as the campaign progresses. The difficulty level plays a big part in how fast this adjustment happens. So while the AI has less of a material advantage, it may now start to act slightly smarter than it used to. This is still a work in progress and will continue in the next few versions.
The promised battle scenario is also in 0.29, but it is not as fine-polished as I would have liked. It's playable for now, but expect some improvements coming to it in the future.
A ton of fixes, big and small, are also included of course.
As for the demo, go ahead and try it: I decided to throw in the campaign mode after all, the only restriction is that higher-level techs are locked out in the demo. You can research everything up to Cruisers, but after that research is blocked. You can, however, continue your demo save in the full game without a problem.
Overall, I hope you enjoy Solar War version 0.29! Let me know how it goes.