The story is basically told in a letter from Jan Ors to the a Rebel Leader, Mon Mothma. The game took place between Episode 3 and 4 where Mon Mothma hinted of a freelance mercenary (Kyle Katarn) who infiltrated an Empire base to steal the plans of the Death Star. During this time, Dark Forces (DF) was surrounded by games like Descent, Duke Nukem, Doom and its trillions of clones. It was also during this time when Lucasarts was at an all time high in making good use of the Star Wars license and this game is no exception. The graphics have aged well but I couldn't get over the limitation of sprite animations in the 3d world. I'm probably one of the few who really didn't have much satisfaction in playing Doom and its many clones. Call me bias. However, DF had one thing going for it:
It was still Star Wars.
The game's graphics stood out at that time but it wasn't so much the graphics. It was the sounds. I remember playing a demo of it in Comp USA and was sold in buying it. There were weapons in the game that screamed Star Wars and then there were some weapons that seemed pointless or more flashy than functional. The level design made you feel like you were walking around a bonified area from Star Wars and it felt cinematic shooting and running pass Stormtroopers as you hear their rifles blasting while they shout "Stop, Rebel scum!". It brings great feelings when the soundtrack happened to cue up as you escape to the next door. Before the full 3D breakthrough of Quake, the game also allowed you (much like other FPS at that time) to look 50% up and 50% down. You couldn't look directly above or below you thanks to the limitation of sprites and 3D engine. This made crouching useless and jumping a chore. It was one of the most annoying and gimmicky reasons which kept me from buying other FPS games at that time.
The game had many weapons to play with. Some of the weapons were outrageous. Outside of the standard Star Wars fare (Bryar pistol and Laser Rifle) you would come across some really potent firepower. You never see these weapons in the movies but they are really fun to use. The Repeater gun was my weapon of choice since it had an extremely fast fire mode which pushed enemies back when they make contact with the ammo. Other enjoyable weapons included the mines, assault cannon (equivalent to Doom's BFG), and the enjoyable Mortar Gun. It lobs huge mortar shells, takes up half your field of view, and cleans out groups of baddies. However, despite these weapons, many people wondered if we could find that one weapon everyone wanted to use in the game...
Anyway, it wouldn't make any sense to have the lightsaber if Kyle Katarn was not training to be a Jedi or didn't have any inkling of force powers. According to the Star Wars universe, he would probably hurt himself.
Dark Forces is a good game on many different merits and is still playable during this time. If you're into starting the Kyle Katarn marathon, you should start with this game.