This is a prime example of "John-Carpenter-before-he-went-insane" beauty. This is also pre-Halloween shit.
A cop station is shutting down. On its last night, the skeleton crew running the station and some convicts diverted to the station have to defend themselves from a gang.
There are a number of reasons why this film was effective & didn't suck as much ass as its remake.
Firstly, there's the direction & cinematography. The outside scenes are shot almost entirely at night. If you've ever been in a run-way-the-fuck-down part of town after dark, you know what it feels like. Imagine putting that onto film. John keeps the pace very rapid (the running time is maybe ninety minutes). He also manages to make his scares count when they should.
Secondly, there's the writing. The gang is written to be as organized as a private army. They act accordingly. This isn't a collection of unthinking, generic villains. It's a fucking death squad. 'Course, the folks inside the cop station aren't written as idiots, either (at least, not the ones that survive).
Next is the acting. For a few films, John had an unofficial acting troupe that worked for him. People in this group included Jamie Lee Curtis, Nancy Loomis, Charles Cyphers, & a few others. This was John's first big film (unless one counts "Dark Star"). So, this is where he first worked w\ most of them, Jamie Lee excluded. This isn't great acting. Hell, most of the time, it's not even good acting. But it is adequate. The remake is replete w\ too much over the top shit.
Verdict : 3.5 stars. A bit too short. Also, a couple script rewrites could've added some serious thrills. As w\ most of John's early work, some polish was needed. This didn't get quite as much as it needed.