Kolakoski

Score: 62.11 (pass)

#!perl -l
print map{-@@+push@@,($==$ARGV[$|--])x($@[$.++]||$=)}1..pop

Score: 65.11 (pass)

#!perl -l
print map{$==$ARGV[$|--];-@@+push@@,($=)x($@[$.++]||$=)}1..pop

Score: 65.12 (pass)

#!perl -l
print map{$==$ARGV[$|--];-@@+push@@,($=)x($@[--$_]||$=)}1..pop

Score: 66.14 (pass)

#!perl -l
print map{$==$ARGV[$|--];-@@+push@@,($=)x($@[$_]||$=)}0..-1+pop

Score: 69.14 (pass)

#!perl -l
print map{$==$ARGV[$|--];push@@,($=)x($@[$_]||$=);$@[$_]}0..-1+pop

Score: 71.18 (fail)

Usage of $) rather dubious.

#!perl -l
map{$==$ARGV[$_&1];push@],($=)x($][$_]||$=)}0..$);print@][z..-1+pop]

Score: 72.18 (pass)

#!perl
map{$==$ARGV[$_&1];push@@,($=)x($@[$_]||$=)}0..666;print@@[z..-1+pop],$/

Score: 72.19 (fail)

#!perl -l
map{$==$ARGV[$_&1];push@],($=)x($][$_]||$=)}0..255;print@][z..-1+pop]