Kolakoski

Score: 74.22 (fail)

#!perl -l
for(0..300){$^=$ARGV[$_%2];@q=(@q,($^)x($q[$_]||$^))}print@q[0..-1+pop]

Score: 75.22 (fail)

#!perl -l
for(0..200){$^=$ARGV[$_%2];@q=(@q,($^)x($q[$_]||$^))}print @q[0..-1+pop]

Score: 77.15 (pass)

#!perl -l
until(/.{$ARGV[2]}/&&print$&){/.{$b}(.)/;$^=$ARGV[$b++%2];$_.=$^x($1||$^)}