Feh. Standard golfing got down to 157 (you don't count the shebang line) while keeping the boo and congratz and the like.

However, a good golf would be something that can be written into a function. So, maybe if you changed it so that the result of hangman'ing is return as a 1 or 0 and all the strings are either handled by the caller or passed in. In that spirit, I give you 134 :

sub h {
@w=pop=~/./g;for$a(1..pop){print$_[0],$/;$_=<>;chop;$l{$_}++;@l=map{$l
+{$_}?$_:'_'}@w;print@l,$/;return 1if!grep{!$l{$_}}@w}
}

if (h('guess', 7, 'foobar')) {
    print "Congratz!\n";
} else {
    print "Boo!\n";
}
[download]

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/me wants to be the brightest bulb in the chandelier!

Vote paco for President!