Want to know if it's worth your time? Okay, I'll give you my overall impressions, leaving out spoilers.
The early part certainly has a horror movie feel, but not just any horror movie: a cheesy horror movie. It hits a bunch of basic cliché points pretty fast in the first few minutes: there's a focus on partial nudity, a cheap not-scare played for the humor, along with the plot-wise establishment of a dead body and a killer on the loose.
Stiles strikes me as being in-character, at least as far as the things he says and the decisions he makes. He was written mostly like the old Stiles, which is to say a jerk, so he's talking that way and going through the motions, but I think the actor is not quite into the role, so it does fall a little flat. He's also got a bit of the BWOC character Merton Dingle mixed in.
The first special effects we see are slow-motion shots of a dropped asthma inhaler and some CGI deer. They would be bad special effects for a movie, since it's easy to tell they aren't real, but for a TV show they're pretty good. A little overused, but not technically bad. There's also some very obvious product placement for the iPhone.
And when we see the first werewolf, it's very CGI. It looks like a video game character. Wisely, the camera doesn't linger on it much and mostly we get a jumble of confused jump-cuts to disguise its inadequacy. The werewolf howl is pretty bad. It sounds nothing like a wolf howl, or like werewolf howls from other shows/movies. It sounds very odd and electronic.
Within the first ten minutes there are already some minor plot holes. They aren't terrible and could easily be explained by characters being very stupid, which makes sense, as they're teenagers. A few more plot holes pop up throughout the episode, but none that stood out to me as glaring.
The high school scenes have moments reminiscent of all those classic 1980s films, with staring contests, ignoring behavior from the popular kids, typical bullies, a focus on sports as a marker of self-worth, classes being presented as boring, minor delinquency by everyone used for fun, awkward parental moments, and teenagers generally jostling for dominance among themselves. In re-creating the atmosphere of one of these old movies, it does well.
The main character, named Scott McCall instead of "Scott Howard" like the original, is a generally likable guy. The actor shows a range of emotions at the proper times, emotions that are generally well-matched to the material. Occasionally the acting feels a bit flat, but it's usually okay. As long as he's not really worked up his acting seems fine.
It is easy to follow Scott's story and to root for him. He's a very average "everyteen" type of character. A little bland, but not bad. However, the producers are certainly taking a cue from Twilight. There are plenty of shirtless and otherwise half-nude scenes for Scott, so if you're looking for male fan service, there's no lack of it. For female fan service, so far there's almost nothing, unless casting particularly attractive women counts.
There's a minor amount of symbolic theme naming (Allison Argent, for example) but it is mild enough to not be obnoxious, and I've seen far worse done in many werewolf films (theme naming is a common sin in werewolf fiction).
The episode also hits a LOT of the usual plot points for werewolf fiction, including the standard before-transformation little clues, the research montage and so on. These feel kind of forced, as if it's a plot by numbers, going out and collecting all the plot coupons. It isn't done horribly, but if you don't like this sort of thing it ends up being a kind of drudgery while you wait for any original plot points to arrive.
Scott's transformation special effects are much better than the earlier CGI werewolf, pretty good for TV, though still looking fakey and certainly below the standards of movies. He doesn't look at all like the original Teen Wolf (who looked like a yeti), instead he has something more like the hairy-guy-with-fangs-and-claws look.
The episode has a build-up to a fairly predictable climax and a little twist ending that won't surprise you if you've been watching the previews.
My overall impressions are that it's not great, but it's not horrible either. It is, however, very predictable (but who knows, it might improve in later episodes). It's certainly a drama, not a comedy. If you're a werewolf fan, I think it's probably worth watching, though I don't have high hopes for it. I do think they key to enjoying it is to not compare it to the original, to think of it as a completely new thing.
Some other basic information revealed in the first episode:
The original film's hereditary werewolves have been replaced by biting as a transmission mechanism.
A bunch of completely new characters have been added.
Scott lives in the town of Beacon Hills, California instead of the original's Beacon Town, Nebraska.
Basketball has been replaced with lacrosse.
The power couple of Mick and Pam has been replaced by the power couple of Jackson and Lydia. Like Mick, Jackson seems to be the prime bully, but Lydia, instead of filling Pam's role of being Scott's crush, has instead become Stiles's crush. However, she does seem to be eyeing Scott at times.
The character of "Boof" does not seem to have been replaced by anyone. Boof is entirely absent.
Scott attends Beacon Hills High School, which looks surprisingly 1980s (or maybe not so surprisingly, since this is MTV).
Stiles's father is the sheriff.
Scott works at a veterinarian's office.
Instead of Scott having a completely missing mother who is implied to be dead like in the original, Scott has a mother. However, there does not seem to be a father.