This was my very first mod, it's very clunky, old and not very well made. You might still find it somewhat enjoyable on a rainy day or if you are dying for extra half-life content. "Missile strike imminent is about a citizen located in the sewers somewhere in the outskirts of city17, after recent news of a rocket being launched by the combine, you are tasked to find your way to the combines base of operations and destroy the warhead at any cost."
Not a bad little mod if you ask me, but it is in serious need of polish in level design.
The gameplay itself is very straightforward, until it ends abruptly. Give this a go if you need another half-life fix, but otherwise, your time is better spent elsewhere.