I never popped a review here, huh?
Just in case, even thouh I'm spoiling nothing.
Might've been a year since I first played this, but it was amazing. Not only is it fun, but it had immersion. I was a skeptic at first because I found the Age of Aquarius (BP1) to be an above-average-but-not-the-best campaign simply because the whole magical, alternate universe and the alien war lacked the human element. There is no reason to feel sorry for the Shivan, and the deus-ex-machina Vishnans felt very cliche. War in Heaven, on the other hand, is truly a human conflict. Vishnans were retconned (or were they?) to be a species that can't be fully trusted, and everything that happened can be scientifically (in a sense) explained. Everything about it feels real, even the politics.
While some of the ships look good, the best part regarding the graphics are the effects. At the time, War in Heaven were using things never before seen. In fact, WiH helped influence the Mediavps, the community's graphical enhancement. And let's not forget about the planets. The details on the bitmaps are astounding. Mars, for example, is terraformed. Unlike other cheap scifis, Mars is "realistically" terraformed for the time, and it doesn't cover the whole planet. Also, Earth during one missions is lighted up on places that currently do not have lights but can be predicted to have lights in the future. These subtle differences make the world a much more believable place. Another bonus would be the recommended lighting. It helps establish a mood, and it works beautifully. The only thing bad about the graphics would be the unoptimized models, but we'll talk about that later.
The story (including the backstory) shines here, and I would say that it is the best in any game/mod I've played. It is very well-written, and the characters are easy to relate to. This is novel. There is no black-and-white. There's just gray, even the terrorists. Where a scifi book may have a glossary in the back of the book for special terms, the game's equivalent Techroom database entries is extremely detailed. You can tell that the BP team did their research by the way the characters speak in-game, which is a lot more than what most of Hollywood do for their movies. Oh, and anything can be an allusion to anything. Very deep.
The gameplay of the first part of War in Heaven is pretty much FreeSpace 2 with a lot of subtle-but-awesome tweaks. The AI is much smarter and does not cheat, for example. Most of the weapons and spacecrafts are useful unlike retail FS2, where you only need to reuse the same three ships to win. And the missions aren't at all repetitive. There's even a mission where you can command a frigate! This was revolutionary at the time. The only gripe that anyone might have is the long narrative, and dying before a checkpoint when that happens is very annoying. The lack of voiceovers doesn't help, either. One last problem was that the game bogged down at times because of the lack-of-optimized ships. However, these flaws may be remedied some time soon.
In summary, this is the best mod I've ever played, and I've fallen in love with the story. The graphics are above average, especially the special effects, and the gameplay is excellent. The only complaints that I have currently are the lack of voice acting and the lack of optimization, but those will eventually be fixed. All in all, a gem in the FreeSpace community along with Windmills and Vassago's Dirge.