The first and most obvious problem with the game is bugs. LOADS of bugs, and many of them very serious (i.e. game breaking). Fortunately, the SFC 2 community has been working to address these problems, and is still active and helpful. If you get the game, definitely get the latest patch. It will save you a great deal of pain.
About that learning curve- only a Trekkie who wants to push every one of those funny colored lights on the TV show would ever appreciate an interface like this. There are enough buttons to make starting the game discouraging for beginners, though the tutorials do a relatively good job of explaining things. In single play you can also pause to issue orders, but for multiplay you really have to know the hotkeys. There are more hotkeys in this game than any other I've played- literally the entire keyboard is used.
One of the worst problems with this game is difficulty. I'm not sure how the designers come up with missions for you, but I suspect it's purely random. It's entirely possible you'll accept a mission that is utterly impossible, given the firepower you have at any particular point. Until you have three battleships, it's recommendable you save in a new slot after every mission. My first mission in SFC 2 was a blast- literally- when they stuck my poor little frigate up against a space monster that didn't stop firing plasma torpedoes. The good news is you can't ever get completely wiped out, since they always give you a frigate to play with. The bad news is if you keep getting wasted, you'll never get anywhere and the required missions will quickly become impossible to complete.
Though the game has a 3-D look, it's not really a 3-D experience. You maneuver along a single plane with no Z-axis to speak of. Pretty much all the maneuvering you do is throttle up and down, and steer left and right. You can't reverse or roll your starships. What is kind of funny is that there's no collisions despite the fact that you're all on the same level. You can fly right through enemy ships, and you really should because it's impossible to miss at that range. I can see why the designers didn't allow you to maneuver with depth, as this would make lining up your weapons even more impossible than it already is, but this makes the game play in a very 'fake' manner. It also makes it impossible to hide from enemies, even if you have cloak.
The starships in the game behave more or less like they're 'supposed to,' which does NOT mean that everything goes like it does in the movies. Photon torpedoes seem to have terminal homing problems and almost never hit in 'normal' mode. You can load up your ships with missiles, mines, shuttles, and fighters for more reliable damage, but things largely degenerate to phaser/disruptor slugging matches. Those, by the way, take so long to charge that even an easy battle can last ten minutes.
The game's graphics are good, even for now. Weapons look like they do in the movies, and the ships have good detail. There are enough unique types of vessels to make the game fun to watch, though there aren't actually as many unique designs as advertised. The vessels you see here are largely the older Trek ones- not including Next Generation, DS9, etc. There are also many ships that don't appear anywhere, but Taldren made up. They did a good job modeling them, however, so they don't look goofy.
The game's sound really needs work. The soundtrack is good and the weapons sound like they should, but you'll immediately notice how scarce the voiceovers are. Essentially, you get alert reports, some damage reports, and Sulu's voice in the tutorial. That's pretty much it- the rest is text flashed on the screen in ridiculously small print, and sometimes faster than you can read. Most of the plot is conveyed in this manner, so keep a finger handy on that pause button for these times.
The missions, in addition to being occasionally bugged, are sometimes ambiguous. You are given orders at the start, and it's all or nothing to the finish (no saving in the middle). Some are characterized by long stretches of flying through empty space, which is exceedingly dull. You command up to three starships, but only one directly. You can issue general commands to the others, but they sometimes behave quite stupidly. They also follow you no matter what, which can be good or bad. Sometimes you really want one of your ships to withdraw from battle, but the only way to do this is take command of it yourself and fly off. Unfortunately, the others will also tag along. Then again, this is exactly what you want when you run into an impossible encounter.
My last gripe is the naming conventions. They use a rather counterintuitive system of letters, pluses, and dashes to designate ships. Even worse, each race has different designations for equivalent ships. It's very important to know what the designations are, since you really don't want to charge your frigates at a line of dreadnoughts. The only good way to do this is to spend an eternity in the tech library, which is somewhat less than fun. If Trek ships looked more distinctive, it could be easier to tell the various types apart. I think they do in newer episodes of the series, but these are the old ones and they all look similar.
Though in general I think SFC 2 is a good game, it could have been a whole lot better. I'm curious to see where this franchise is going, and might even get the sequel. However, due to the problems with this one, I think I'll wait for it to get cheaper.