I feel like I should let you know up front I'm not the world's biggest Trekkie (in case you are). My experience with the franchise so far has been watching a lot of The Next Generation reruns on UPN back when I only had broadcast TV, and watching a few of the funnier episodes of the original series on Youtube, like the one where they stole Spock's brain or the black & white cookie aliens were having a civil war.
Still, I feel like that's enough experience to have a handle on some basic principles of the series. For example, that the Federation tries hard to avoid combat wherever possible. And while ship-to-ship combat isn't exactly infrequent, it usually ends with the Captain finding some clever way to minimize casualties and bail, not the Enterprise wading in all macho shooting up five Birds of Prey or whatever all by itself.
Welp. As the "Tactical Assault" in the name might indicate, that's all out the window with this game. Every mission contrives to find some way to put your wessel up against some ludicrous number of enemy ships and then expects you to actually kill them all. Pretty sure my kill count was higher in this one than it was in Wing Commander when all was said and done.
I guess you could set up a plot contrivance to make this make sense within the Trek universe, but this one didn't really bother. It's set just after the original series, with Admiral Kirk running shit and an uneasy truce maintained with the Klingons. You'd think in such a setting, everyone would be walking on eggshells to not trigger another intergalactic war, but nope -- pretty much every mission devolves into brawls in the Neutral Zone with Klingons, Romulans, or various rogue smugglers and raiders.
Combat is kind of comical; you basically have to constantly spin so that enemy fire impacts different areas of your shields while firing your fore and aft phasers. If you want to use a photon torpedo, though, you have to face the enemy and manually aim it. Photons and phasers also take some time to recharge, and if you want to recharge shields, you'll have to power down weapons and protect the recharging section from incoming shots.
This could have been an OK system, but the combat arenas are not well-designed. Your ship is almost always outnumbered by two or three enemies right from the beginning of the game, and attempting to block all their incoming fire while also getting in position to deliver necessary photons is headache-inducing. Adding to the frustrating difficulty is that every area has all sorts of debris, moons and even planets strewn about, which are often off-camera when you're moving about leading you to suddenly run into them while focused on the three frickin' enemies all around you and take hull damage. Recharging shields also feels pointless given all the Space Junk and the battering your other shields take from the multiple enemies buzzing around shelling you with photons while you're waiting.
In between missions, you get two points to put into upgrading an area of the ship of your choosing. There's a particular sequence you have to upgrade things in, though, or you'll be irrevocably screwed in tough later battles and probably have to start the whole game over.
There's lip service to "non-combat elements", in that missions will usually have you scan planets, talk to various people and do a little investigating. This proceeds on a linear track, however. And this being a Bethesda game, when you're called upon to make a choice, your options are basically Be Overly Trusting or Be A Massive Dick. ProTip: Massive Dick is never the right choice.
Since this is set after the original series, involvement from the original cast is limited to an opening narration from The Shat. You and your crew are generic moops represented only by static, squishy headshots. You're also a rookie captain at the outset of the game, so you don't get to tool around the galaxy in the Enterprise.
A DS version was also made simultaneously, and maybe the touch controls really add something to the experience, I dunno. I recommend skipping the PSP version, however. It's just slow clunky frustrating combat paired with an uninteresting story, and not even the nicety of fanservice for the Trekkies.