An attempt to capture the essence of Wing Commander that almost succeeds. Almost.
I've played this game through three times now -- it doesn't take long, really -- so I think I've gotten a good enough handle on what the game is about to make some observations about it.
The most important part of this sort of game is gameplay. Unfortunately, this is one of Project Sylpheed's weakest areas. The actual ship movement isn't bad: it makes sense and works well enough. However, engaging in some of the other control functions is sometimes difficult, and often cumbersome. For example, you have to double pull the right trigger to hit your afterburners, during which your maneuverability is much reduced, but after you release the trigger the afterburners continue to fire for a while, making placing where you want your ship to end up a tricky affair.
Worse than the above is the difficulty in determining your orientation. This is, IMO, especially perplexing. While I can accept that a space-based fighter craft might not have a "ball" that tells them their orientation with the horizon, with the poorly implimented radar it is easy to get yourself so turned around that you don't know which way to turn to line yourself up for your next target. Many times I found myself using trial-and-error to figure out which way to turn, wasting precious time in the process.
The graphics themselves were good. There were a few times when I noticed some studdering, but for the most part, my 360 Elite didn't seem to have any problems. Sound was also decent, though I found the Hanger theme to be somewhat grating on my nerves. Voice acting was very good, but sometimes over-the-top (especially Ellen).
The plot was... passable. Sort of. Many parts were overly dramatic, others seemed to be entirely implausable. For example, how could the Terrans not have known about such a massive fleet build-up by the members of the ADAN alliance? Why would ADAN citizens condone the destruction of entire worlds? Sorry, just not at all plausable. The Devs need to go play Freespace.
Some additional, nit-picky observations: The game uses weird terminology, both in terms of military ranks and in ship type names. Some military people have ranks like Colonal or Major, while others have Admiral and Commodore. I wish the Devs had did a bit of homework on that. More annoying was the "Ships and Fighters" issue. At first, I didn't understand the difference in how the game used the names. I also wish they'd used the term "Capital ship" to refer to carriers or battleships, since that is what they are. I suppose this all falls under translation issues (the game was made in Japan), but it still causes confusion and seems sloppy to me.
In conclusion, though I've bashed the game quite a bit, I think it has its moments, and is reasonably fun to play once you start getting used to the funky controls and cluttered screen. It's not in the same league as Freespace 2 (but then, what is?) and its short length means it loses its freshness rather quickly. But if you don't take it too seriously, you can still get some enjoyment out of it while thinking about how easily it could've been a much better game.