I always found it curious why Jedi Outcast and its sequel, Academy, dropped the Dark Forces moniker. I had figured it was for brevity and clarity, since Jedi Knight III: Jedi Academy - Dark Forces IV, the name I would have chosen since it's a badass mind♥♥♥♥, alas isn't marketable.
But I get it now. It's because the original Jedi Knight: Dark Forces II was very much a Dark Forces game, moreso than a Jedi Knight game. This is due to its pretty awful lightsaber implementation versus its pretty awesome gunplay. The original Dark Forces, just to be clear, had no lightsabers. It didn't need them. For the sequel, everybody wanted to use a lightsaber, so LucasArts tried to deliver. Unfortunately, Kyle Katarn couldn't block any incoming shots effectively, and I guess you could say it's because he was still in training and he sucked at being a Jedi. He was better at being a gunslinging mercenary, and thus the original Jedi Knight game made for a better shooter than a lightsaber sim. Hence, Dark Forces II.
The Raven Software sequels are both lightsaber-centered, and ironically, they're both ♥♥♥♥ty shooters. Gone are the Dark Forces days where the gun fights had weight and speed. Now, instead of strafing around like madmen, stormtroopers are content to pretty much just stand there as you shoot at them, and fire back at such a constant rate that you could tap your foot to the blaster's beat. As you sink your shots back into their armor, they stand still, unflinching, as if they didn't realize they had lasers burning through them. It's all very smoothly animated, like butter, but it's also really boring.
The guns are also wildly ineffective, since as an alternative, you can run through these guys with your lightsaber flashing, cutting each one down with one stroke WHILE managing to block every incoming shot automatically by just having your lightsaber equipped. This game is exceptional at teaching you just how pointless the guns are, which makes it surprising that you still have to choose your weapons at the beginning of each mission.
Once the Dark Jedi start appearing, the game gets good, after a very dull first few missions. I was initially amazed at their ability to cut me down so quickly, and I got frustrated, thinking that the combat was just about swinging the lightsaber wildly and getting lucky. While the sabers don't connect in clear offensive/defensive poses very often, there still is a strategy. For one thing, a few defensive force powers are critical to surviving the tougher Dark Jedi, and once you figure out to map them to keyboard keys, the fighting gets a lot easier. (Of course, the game doesn't teach you this.) For another, circle strafing becomes the best tactic, since most of your attacks get blocked when you swing head-on. The resultant visuals look like a sort of randomized dance, lacking choreography but still well executed. And when you get the kill, the camera goes into a slow-motion 360 twirl around your custom-made character as he/she lands the finishing blows, and that never gets old.
You can loosely compare the Dark Forces games' visual style to the original Star Wars trilogy - grungy, old, rough around the edges, beautiful. Likewise, you can compare the Jedi Knight II sequels to the Prequel Trilogy - flashy, pretty, colorful, smooth.
Since the story, environments, music (the John Williams themes are cut up, out of place, and butchered here), dialogue, etc. are all pretty bad (or at the very least outdated), the game relies on its blend of lightsaber combat and force powers to keep you interested. Those two elements are good enough to merit a playthrough, which is why I recommend the game.
Graphics note: The max resolution available is pretty awful, but can be modified with a config edit (check the forums) to use your HD monitor's native setting. I got it running at 1440p, which looks remarkably good, but the game loaded with a blank white screen every 20th time or so, forcing a game restart. Annoying but not game-breaking, and worth it for the picture quality :P