Splinter of the Mind's Eye was the first original Star Wars book -- or at least, mostly original. See, Alan Dean Foster was given a few specific instructions and restrictions when writing this book because it existed mainly as a sort of back up plan. If the first Star Wars movie was successful Lucas would proceed with making the expansive and expensive trilogy of his dreams -- which, as we now know, is what happened. If it hadn't, Splinter of the Mind's Eye would be used as a basis for a lower budget sequel. As such, many of the creative choices were dictated by a hypothetical budget: less scenes in space (only one in fact), misty jungles and caves that could be made on the cheap, and a lack of the most expensive cast member (Ford/Han).
This is all fairly well known at this point, so I was a little surprised that the introduction made no mention of it. The edition I read included an introduction by George Lucas written around the time of the Phantom Menace. The novelization of the first movie had a similar introduction where Lucas was fairly forthcoming about certain details about the production of the book. Here, Lucas merely speaks of it as the first step in creating the Expanded Universe. It's standard mythmaking type stuff, talking about how Lucas realized how there were more stories in his world than he could ever tell alone, and somewhat misleading considering the circumstances. From my admittedly slapdash research it may be that Lucasfilm wasn't open about the "true origins" of this book until Pablo Hidalgo's Essential Reader's Companion in 2012, which is a shame. I understand that peeking too much behind the curtain can be contrary to Brand Management, but it's very useful for understanding some of the choices made in this book.
Jumping way ahead, one area where this knowledge is useful is the final confrontation between Luke and Vader. If one solely knows the movies, then the fight between Luke and Vader in Empire is their first time encountering each other since the battle at the Death Star. This heightens the drama, as we can assume much about Luke's stewing hatred toward the Sith Lord who cut down Obi-Wan and Vader's own grudge against the pilot who escaped him. Any story between A New Hope and Empire where the two encounter each other outside of a "just missed him" situation undercuts this drama, making the Cloud City fight just another encounter between the two (albeit one with a shocking revelation at its end). However, in this case we can forgive Foster for Vader's inclusion seeing as it was almost certainly foisted upon him due to the book's nature as the potential basis for a sequel. Had Empire not been made, then of course Lucas would want Vader to appear in whatever sequel he did get to make. It's a reasonable instance of Lucas hedging his bets, rather than simply adding more Luke/Vader fights just for the sake of it, but without knowledge of the book's genesis one would reasonably consider it an instance of the latter.
That being said, what an anticlimactic final battle. After some fairly intense action, including Leia getting to use a lightsaber (despite frequent insistence at this point that she is not force-sensitive), Vader just kind of... falls in a hole. Odd.
At this point Foster had about as much experience with these characters and this world as anyone else save Lucas, so it certainly feels properly "in continuity" with the first movie. Some things might feel a bit odd and out of place with Star Wars as we know it now, but to the extent one can restrict one's view to just the first movie and this book they largely feel in harmony with each other. One of my favorite examples of this is Leia's PTSD from her interrogation. While the exact details of whatever happened with her and that menacing droid in A New Hope remains vague, Foster takes the reasonable position that whatever happened would have greatly affected her, as torture always does. However, he manages to depict this in a way that doesn't detract from Leia's now well-known characterization as a tough and capable wartime leader. While she may have been a victim, she is not weak. It's a side of Leia that I'm not used to, and one I think Foster handles well -- the way the movies otherwise just have her interrogation as a Thing That Happened and not as a traumatic experience seems lacking in comparison.
Another thing that Foster gets into that is generally only implied by the movies (movie, singular, at this point) is the racism of the Empire. This is a major theme in many other EU works, and although it is not exactly stated in the movies is shown by the human-centric nature of the Empire compared to the more diverse nature of the Rebellion and fringe planets like Tatooine. Foster drills more into the Empire as an occupying force in an alien world, with the native Mimbanites being actively and categorically oppressed by their colonial masters. It runs into some perhaps problematic elements when considered as an analogy for real world imperial colonialism, with the Mimbanites being shown to willingly debase themselves for liquor, but on the whole Foster gives a more thoughtful and concrete example of the repressive nature of the Empire (granted, blowing up a planet is fairly repressive).
One funny example of the context of the early EU changing with later movie releases: Luke is down so bad for Leia. Granted, he is in A New Hope and Empire, too, but the internal monologue when he thinks about her body against him and such makes it feel a bit more "oh noooo."
On the whole, Splinter of the Mind's Eye is a solid first entry in the novels of the EU. Foster is a more-than-competent writer, and he introduces a few concepts and themes that will later become commonplace in the setting (force-sensitive non-Jedi, Imperial xenophobia, ancient alien civilizations with ties to the force, etc.). Most of the novels faults are related to things beyond his control, though I'm still a bit baffled by that ending. If this had been adapted to film, surely they would have come up with something a little more exciting than "Vader takes a wrong step and falls."
