A lot of the characters seem one-dimensional so far; they present no depth or interest (Xander, Cordelia, Giles, and most definitely Jesse), which needs to be established in the first episode. Jesse is a disaster waiting to happen, if he is going to be on the show, he needs to do his job and get the hell out of there. Not only is Jesse one-dimensional, to me he seems to be better suited as a plot device (it's a good thing he does leave). He also just seems like an extension of Xander, and seems to be a third wheel. The Villain characters are also far too one-dimensional, not only that, they are clichd. The Master and his followers are pretty cheesey, and provide only a small interest.
I didn't really appreciate the setting either. The idea of it is actually fine; it's the way it was set up at night. At night you can tell that they were filming this in a warehouse. For example, when Buffy meets Angel, the lights in the alley don't look much like streetlights to me. Also, when Buffy has Angel pinned you can see, in the background, the warehouse door open up into daylight. This setup was pretty sloppy; I mean the least they could have done was shut the door.
There are also problems with the plot as well. For one, there isn't much plot at all, not until the end at least. The episode focuses way too much on establishing the characters, which in many respects is a good thing, as long as you're not overcrowding the plot. They should have developed the plot and the characters at the same time. We're rushed into the plot at the end of the episode, rather than building ourselves up to a decent cliffhanger. So far all we know is that the Master is stuck underground and wants to get out. They make the plot too unimportant to the audience so that the audience doesn't appreciate the cliffhanger as much.
What happens in most first episodes, happens in this one as well. The actors tend to overact in their roles because they are uncertain on how to act out their character. This problem distinguishes the first few episodes from the rest of the series, in terms of acting at least. Plus David Boreanaz isn't a very good actor at this point.
The score is awful. It is way too cheesy and it over exaggerates, making the moment less than it is. The score adds nothing to the show, in fact it seems to take away from this episode, and makes the episode a little boring.
Alright, let's get into the more positive aspects of the episode.
Despite some discrepancies in the characters they are well established and each character has their own unique personality. Buffy is very spunky and tends to live in the now causing conflict with her "slayerness" as she attempts to have a normal life; Xander is very boyish, geeky, and comes off as a bit of a loser; Willow is cute, nerdy, and seems to be very smart, she also has a crush on Xander, which becomes a huge part of her character down the road; Giles is dedicated to his job as a Watcher, which brings him into conflict with Buffy, as Giles seems to represent part of her slayer qualities; Cordelia is the bitch of the show, who is completely devoted to being popular and doesn't care how much this might hurt someone, just as long as she stays popular, she also seems to represent who Buffy was, which is probably why Buffy appears to have success talking to her at the beginning of the episode; Angel is mysterious and is definitely hiding many things which becomes more apparent in the next episode. I like the chemistry and relationships all these people begin to develop, it definitely becomes a big part of the show.
I also like the way they name the town: Sunnydale. It has a certain irony to it: SUNNYdale. The name sounds so lighthearted and happy, when in fact the town is most certainly not.
The plot also offers a nice way for the characters to interact and connect through problems. The plot, though not well established yet, is entertaining so far.
The theme of this entire series is presented to us quite clearly without it having to really be mentioned: in the end you must except who you are, even if you don't like it. The fact that Buffy goes after Willow to save her from the vampire, shows that she is drawn to her duty as a Slayer, even though she doesn't want it and never asked for it.
Overall, I enjoyed watching this episode, despite some of its flaws. The plot needs to be more addressed, and the production setup and actors need to improve. Other than that he characters are well established and have room to grow, despite minor problems, and the theme and meaning of the show become quite clear to us in this episode.