Haven't done one of these in a long time. My comprehensive review.
The Good:
The music is mostly good and sufficiently fast-paced for the sort of combat in the mod.
I'm actually pretty glad to see Ra's Lizard ships finally got used, since I wasn't sure anyone even remembered them anymore.
The catapult launch was a nice touch. (Which was never really used again! No, flying to Earth doesn't count!)
All these old assets nobody ever used, jesus. I half-expected to encounter my never-completed Akula model at any moment.
The Flyssa is hilarious, if not terribly useful. Actually I could say that about most of the missiles.
Silly Chapter 2 is a welcome change for a second playthrough, though not really any better than Serious Chapter 2.
The Bad:
I'm sure you've been sufficiently castigated over the various bait-and-switch bits, so I'll just wag my finger at you.
I got a “no debriefing” screen on Contact.
The lack of targetable markers, much less adding them to an escort list, for the side jobs/no side jobs in the Chapter 2 hub wasn't a wise decision. A player might not even notice them right away; I certainly didn't, and spent a few minutes wandering around.
Dissonance's messages at the start scroll too fast to read straight, and there's no way in hell anyone could speak them fast enough to actually say that.
The same problem occurs during most of Stronghold, doubled by the fact messages with explosions behind them are pretty much unreadable and a lot of dialogue pops up while you're probably making attack runs on the demonic-named cruiser.
Reversal appears to be entirely luck-based. It's far too possible to get caught in kinetic hell unable to move after downing an enemy and then get fried, even on the easiest difficulty. (It's the only time I dropped the difficulty from the Medium-equivalent on my first playthrough.)
Command briefing after the second cutscene has repeated problems with not scrolling as far as it needs to. I blame Random SCP Coder #57.
There is something very wrong with the Losna shield model, as it is bypassed by enemy fire often. This isn't the first time I've seen things like this happen, and I suspect a combination of high-velocity weapons and imperfect modeling, but I don't know for sure. Regardless, it's pretty bull**** to blow up without a shield breach and I've done just that several times, and since nobody talks about it otherwise, I have to assume it's bug. This means there is no reason to ever fly the Losna.
Why does Talos Station care if their reactor melts down, so long as they're nowhere near it when it does? Seriously, just pull your **** and go, it'll be stable for the ten minutes or less that appears to have ultimately taken you.
Several times the screen blacked out and the Repair/Rearm got called for no reason; frequently I was over a thousand meters from the nearest capital craft at the time. This usually meant the mission was a bust as nothing could be done to get it out of this state.
Again with the too-rapid messages when I started the stealth mission.
The Ugly:
You really ought to collect the test answers an easier-to-access place than where they are, it took me quite some time to find Andrew's...actually I take it back, I didn't find that, I found your link to that post via search, eventually. That's how buried they are.
It would have been nice to have somebody ask why everyone look so young, or at least hang a lampshade on it. You didn't honestly think you'd sell us on them being late teens, did you?
The new ships (mostly fighters) you can spot in the two missions before Dissonance aren't added to the tech room after the missions they're visible in, which is a little disappointing considering the mod was good about that until then.
Text with explosions behind it, or indeed most of the effects here, isn't readable. All the pretty effects inhibit the ability to grasp the story or much of anything as to what's going on.
The autoaim feature is pretty much necessary to make the mod work, but much like my experience with it in Wing Commander 3, it's pretty much useless at high deflections or long ranges. It's kind of like having a primary battery of Hornets.
The main menu music is pretty much uniformly terrible and overly loud/fast-paced for when somebody's just trying to read the goddamn Tech Room. This goes some way towards counteracting all the effort you put into said Tech Room.
The anti-subsystem missiles seem to consume excessive bay space for their terminal effects.
The campaign in general appears to have been very poorly balanced for multiple levels of play, and on my second run through on the Very Easy equivalent I found all the missions pretty much exactly as challenging as they were on the Medium equivalent.
Ships in this mod have an extremely bad habit of continuing to fire upon targets which are already dead at 0HP and simply still in the process of blowing up, often in the case of capital ships firing on targets which have visibly broken up but aren't quite finished with their death animation. This looks dumb, and given the speeds of ships and weapons in the mod, can often make it unnecessarily more difficult when three seconds of fire for the PD on the ship you're defending gets completely wasted.
The last mission is laughably easy compared to the three or four that proceed it. Which is probably a good thing.
Summation
Dimensional Eclipse makes impressive use of a variety of mods from a variety of sources to tell its story. It has very good visual effects. It has unique gameplay and a variety of interesting, if not always effective, weapons. The missions are for the most part unique, with the last one (which is at least derivative of multiple sources) being the exception.
But the spit-and-polish stuff in the mod is really bad. From the poor timing of messages to the questionable balance a lot of the time to the low level of player agency in most missions. While the player's impact is arguably critical, the difference between victory and defeat is so minor as to make the missions luck-based most of the time; they may turn on the player's actions but certainly not on their skill. (It's interesting to compare the number of kills the player gets from mission to mission; it's often very, very low but enough to win, and this should be considered a bad sign in a mod so crowded with enemy wings.)
There is a story here. It's not very deep and honestly it's not very good. I was at first impressed by the attention to detail in the Tech Room and the like but that fell away rapidly as things happened and I wasn't given very much reason to care about it, as initially strong characterizations withered and died for lack of ever being reinforced or used. The further into the campaign you get, the less reason there is to care about any of the characters, the less any of them seem to be separate people, the less they even matter. Mars and Earth got glassed, somebody in your unit is FROM Mars, and we get exactly one blink-and-you'll-miss-it line on the subject. Command briefings previously used to convey characterization and interaction disappear, only for one to suddenly reappear before the final mission and even then come off remarkably flat.
I wanted to like this campaign, and at first I did, but Dimensional Eclipse ended up making promises regarding its providing a unique and colorful cast that it didn't keep. The novelty of everything else had worn off by the time it was clear those promises were not going to be kept in Chapter 3, the balance had gotten questionable sometime late in Chapter 2, and there was little or nothing left to hold my interest for the post-Earth sequence. Fortunately, it wasn't very long.