Kolakoski

Score: 65.28 (pass)

...

#!perl -l
$n=pop;push@_,($_)x(@_,$_)[$i++]for(@ARGV)x$n--;print@_[0..$n]

Score: 70.26 (pass)

more tweakage

#!perl -l
($n,$")=pop;push@_,($_)x(@_,$_)[$i++]for(@ARGV)x$n--;print@_[0..$n]

Score: 72.26 (pass)

and again.

#!perl
($n,$")=pop;@x=(@x,($_)x(@x,$_)[$i++])for(@ARGV)x$n--;print"@x[0..$n]\n"

Score: 77.25 (pass)

marginally better...

#!perl
($n,$")=pop@ARGV;@x=(@x,($_)x(@x,$_)[$i++])for(@ARGV)x$n--;print"@x[0..$n]\n"

Score: 98.28 (pass)

first, boring attempt

#!perl
@_=@ARGV;@y=@_[0];$t.=($x=shift@y),push@y,($_[($_-1)%2])x($x-1),($_[$_%2])for(1..pop);print"$t\n";