A nightmare of the wasted lives of alcoholics who fear life and love drink so much that they can't even leave their bar. Makes me glad I find the taste of alcohol unpleasant.
The format and the progression of this play is generally similar to Long Day's Journey Into Night, although with about three times as many characters. Most of the characters are introduced immediately at the beginning of act one: the bartender, about eight alcoholics--various types with various former careers--who are down on their luck, and the owner (who is also an alcoholic). Three or more of their alcoholic friends and one young stranger come in over time. Almost entirely through dialogue, the first half of the play explores their various miseries and lets them interact, displaying their camaraderie (which they always have when they're drinking freely or waiting to drink) and the tensions between them (which always occur the closer they come to trying to reclaim the lives they had before they hit the bottle or before the misfortune that drove them to drink). The third act introduces the only non-alcoholic character, an allegedly reformed alcoholic friend of the others who urges them to stop drinking and reclaim their lives. The rest of the play revolves around this character, and why he quit drinking, and how the other characters react to him. Act Four brings a climax shocking and revelatory, if not as sudden and explosive as that in Long Day's Journey Into Night.
The title refers to an joke the barflies heard from the central character long ago and mention to each other repeatedly. The central character used to tell the barflies a story about his wife cheating with the iceman (which, until the climax, is not taken seriously nor believed true). Its significance is this: the play's climax reveals that the central character's wife did indeed cheat (with an iceman, apparently), but the central character had provoked his wife to cheat by his incorrigibly sottish behavior; he blames himself entirely; so "the iceman" is the misfortune and misery the characters have brought on themselves in one way or another.
I initially preferred Long Day's Journey Into Night slightly, but that was probably a knee-jerk reaction to the last act of that play being more intense and startling. The Iceman Cometh is actually more interesting, just because there are more characters, more events happen and more secrets are revealed (and other secrets of the characters receive only subtle explanations that force the reader to study them more closely).