Here's a short list of some interesting things: phasers[1], lazy evaluation, feed operators[2], grammars[3], meta/hyper operators[4], subtypes[5], multiple dispatch[6].

1: http://design.perl6.org/S04.html#Phasers

2: https://en.wikibooks.org/wiki/Perl_6_Programming/Lazy_Lists_...

3: http://design.perl6.org/S05.html#Grammars

4: http://design.perl6.org/S03.html#Binary_hyper_operators

5: http://design.perl6.org/S12.html#Types_and_Subtypes

6: http://design.perl6.org/S12.html#Multisubs_and_Multimethods