A worthy sequel to Dark Forces
From a purely technical viewpoint, the game has good visuals, for the most part; by 1997 standards, of course. It also has excellent Star Wars themed sound effects and soundtrack, so you'll have no trouble immersing yourself in the Star Wars universe. Also the cinematics are well crafted and, at times, even spectacular.
In terms of gameplay, it's the first Star Wars game to feature lightsaber combat. That's got to be worth mentioning. It also gives you the ability to change your alignment (light/dark side) and once that happens there are alternate cutscenes and two different endings. The inclusion of Force Powers was also a good addition and some of them are essential for advancement through the game.
The selection of weapons is very similar to the one from Dark Forces and some of these weapons have alternate modes of fire. The game even attempts a more modern approach to grenade mechanics, though it falls short of making them truly useful from a tactical perspective. As you progress, the lightsaber becomes a truly potent weapon; not only that you become capable of deflecting multiple incoming projectiles, you can also deflect many of them right back at your enemies. It's quite possible (and entertaining) to kill an enemy using his own weapons' fire against him.
Which brings me to level design. Some of these levels are massive; you get large open areas or long winding tunnels leading you through all sorts of locations. This does give the game a certain epic feel. Also, Force Powers have been integrated into the level design - you will need to use some of them in order to accomplish certain tasks.
Another thing of note is that the game is moddable (you can add improved textures and higher poly characters, for example) and despite it's age there's still a loyal community around the game.
Now onto the less impressive aspects of the game.
Well... some textures are rubbish and bring down the visual appeal. There's one level that has the ugliest grass texture that I've seen in any (hardware accelerated) game.
The acting in the cutscenes isn't bad, but it's pretty mediocre at times. Admittedly I've never been a fan of cinematics that combine CGI elements with real actors. I guess it's just a matter of taste.
The enemy AI has a few bugs: sometimes they will try to come straight at you, getting stuck in the process behind an object/wall and ignoring the fact there's a less direct way of actually getting to you. On occasion you'll notice that although you've left their field of view, they're still shooting in the direction they last saw you in. They also tend to try and shoot you through doors or force fields, obviously with no success.
While I've enjoyed the levels for the most part, some can be pretty frustrating. A confounding factor is the relatively imprecise control of this game which complicates certain actions, especially jumping which is essential in navigating some of the levels. In addition to this, there were a couple of levels that I've felt were needlessly long.
The default control scheme isn't very good in my opinion, but that's easily resolved. Unlike it's predecessor, Dark Forces II allows configuration of its controls.
Another small gripe: during the game you earn points that you can assign the various Force Powers in order to make them more potent. The problems is that, as far as I can tell, the number of points you get is dependent on the number of secrets (secret areas) you discover in the game. From a purely role-playing perspective, that doesn't really make sense to me.
One final note would be that some modern gamers might have trouble running this game with hardware acceleration. Fortunately this has been fixed by the community; there's even an unofficial patch which, it's my understanding, fixes certain issues that weren't resolved by the producers themselves.
The Bottom Line
While the story might not be particularly impressive, nor original, the game and the quality of the cutscenes keep you interested in the developments of the story. It's also fun to play, solving certain puzzle feels rewarding. All in all, if you can get past the 1997 era blocky 3D and low-res textures, the game is well worth it.