My RubyWarrrior level 9 (https://www.bloc.io/ruby-warrior/#/warriors/10954/levels/9) solution.

rw-level9.rb

class Player
  attr_accessor :started, :firstkill
  def play_turn(warrior)
    if not @started
      @started = true
      warrior.pivot!
    elsif warrior.look.select{|space| space.enemy?}.length > 0
      warrior.shoot!
    elsif warrior.look.select{|space| space.enemy?}.length == 0 and not @firstkill
      @firstkill = true
      warrior.pivot!
    elsif warrior.feel.captive?
      warrior.rescue!
    elsif warrior.feel.wall?
      warrior.pivot!
    else
      warrior.walk!
    end
  end
end