Not quite my cup of tea.
The parts they kept were, of course, the way you advance through the game, to play the missions successfully through the first time with the default ship, then you could play the same mission with a different ship, and you can still pick up bonuses such as weapons upgrades. However the game doesnt have the same options as far as viewpoints.
In this game, however, the designers were allowed to use actual locations from the movies -- Cloud City, Hoth, and the legendary Death Star -- instead of made up psuedo-locales. That's a plus. Another difference is that more of the missions take place in outer space, as opposed to all the ground missions in the original game. Plus there is an additional ship -- the B-wing fighter.
I have to admit, the graphics are mind-blowing and immersive. For anyone who's ever wanted to fly an X-wing fighter down the Death Star trench and fire a torpedo into the shaft, this game will satisfy. If you've wanted to fly a snowspeeder over the plains of Hoth, believe me, nothing satisfies better than this game. The way each ship handles is unique, as is the way each responds to acceleration or deceleration. There is also a definite sense of up and down, and spatial awareness. The single largest improvement in the game is that objects that are supposed to look large, ie, Cloud City, look like they should.
However, the game play is a mixed bag. While the graphics and sound effects are definitely a step up, playing the game can be an exercise in frustration. Perhaps with a better controller, like a stick and throttle combo, the game would be easier to play. But as it is, it is too easy to become disoriented during space battles and completely forget where the enemy is. Some other gamers might not have this issue, but it takes away from the gaming experience and certainly takes some getting used to. Also trying to snag and trip up a towering assualt walker is not as easy as it sounds. Here, when you have managed to shoot a walker's leg with the harpoon, the game suddenly switches to a third-person external view, which, if you like to play from the cockpit view, can be extremely distracting and completely blow your concentration.
There is a training mission, but in this you only get to fly a dinky little airspeeder around Tatooine. Separate training missions for each craft used in the game would have been much more useful.
I would say in closing that this game delivers a rather uneven experience -- great graphics and sound, poor controls and game play. Buy it if you are a hard core Star Wars fan. Otherwise, just rent it.