inserting a new 4th intermediate level to better introduce listening

towers/intermediate/level_004.rb

@@ -1,23 +1,22 @@
 #  ----
-# |C aC|
-# | S s|
-# |C>@ |
+# |C s |
+# | @ S|
+# |C s>|
 #  ----
 
-description "You can feel the stairs right next to you, but are you sure you want to go up them right away?"
-tip "You'll get more points for clearing the level first. Use warrior.feel.stairs? to determine where the stairs are."
+description "Your ears become more in tune with the surroundings. Listen to find enemies and captives!"
+tip "Use warrior.listen to find other units, and warrior.direction_of to determine what direction they're in."
 
 time_bonus 55
 size 4, 3
-stairs 1, 2
+stairs 3, 2
 
-warrior 2, 2, :north do |u|
-  u.add_abilities :listen
+warrior 1, 1, :east do |u|
+  u.add_abilities :listen, :direction_of
 end
 
-unit :sludge, 2, 0, :south
-unit :sludge, 3, 1, :east
-unit :thick_sludge, 1, 1, :west
 unit :captive, 0, 0, :east
-unit :captive, 3, 0, :west
-unit :captive, 0, 2, :north
+unit :captive, 0, 2, :east
+unit :sludge, 2, 0, :south
+unit :thick_sludge, 3, 1, :west
+unit :sludge, 2, 2, :north

towers/intermediate/level_005.rb

@@ -0,0 +1,21 @@
+#  ----
+# |C aC|
+# | S s|
+# |C>@ |
+#  ----
+
+description "You can feel the stairs right next to you, but are you sure you want to go up them right away?"
+tip "You'll get more points for clearing the level first. Use warrior.feel.stairs? to determine where the stairs are."
+
+time_bonus 55
+size 4, 3
+stairs 1, 2
+
+warrior 2, 2, :north
+
+unit :sludge, 2, 0, :south
+unit :sludge, 3, 1, :east
+unit :thick_sludge, 1, 1, :west
+unit :captive, 0, 0, :east
+unit :captive, 3, 0, :west
+unit :captive, 0, 2, :north