diff --git a/README.md b/README.md
index 99e043e..cba956c 100644
--- a/README.md
+++ b/README.md
@@ -25,7 +25,7 @@ Configure Options:
 
 # Features
 
-- Recycling Biters - When large groups of biters form on the game map and aren't assigned to a unit group or near a base will be periodically removed and refunded to the ai causes attack waves proportional to the number of units removed.  
+- Recycling Biters - When large groups of biters form on the game map and aren't assigned to a unit group or near a base will be periodically removed and refunded to the ai causing attack waves proportional to the number of units removed.  
 - Breaching - When biters are destroying structures nearby unit groups will come to join them  
 - Frenzy squads - When a unit group gets close to a player or start combat they switch to attacking everything in there path for a set radius or until there is nothing left  
 - Rabid squads - Is in a permanent frenzied state as soon as the group is formed  
@@ -52,6 +52,13 @@ Configure Options:
 
 # Version History
 
+0.15.1 -  
+- Tweak: Increased small spitter damage from 7 to 15  
+- Tweak: Increased medium spitter damage from 15 to 22  
+- Improvement: Replaced game.evolution with game.forces.enemy.evolution  
+- Improvement: Fixed flame-thrower to flamethrower  
+- Improvement: Changed tunnel to have non-zero hp  
+
 0.14.13 -  
 - Reverted: Pheromone generation tweaks from 0.14.11  
 - Feature: Recycling large biter swarms that are stuck (causes a big attack wave, and pops up a message)  
diff --git a/control.lua b/control.lua
index 9493463..324072f 100644
--- a/control.lua
+++ b/control.lua
@@ -166,6 +166,11 @@ local function onConfigChanged()
 	
 	game.map_settings.unit_group.max_group_radius = 20
 	
+	game.surfaces[1].print("Rampant - Version 0.14.13")
+	global.version = constants.VERSION_16
+    end
+    if (global.version < constants.VERSION_17) then
+	
 	-- clear old regionMap processing Queue
 	-- prevents queue adding duplicate chunks
 	-- chunks are by key, so should overwrite old
@@ -184,8 +189,8 @@ local function onConfigChanged()
 						     y = chunk.y * 32 }}})
 	end
 
-	game.surfaces[1].print("Rampant - Version 0.14.13")
-	global.version = constants.VERSION_16
+	game.surfaces[1].print("Rampant - Version 0.15.1")
+	global.version = constants.VERSION_17
     end
 end
 
@@ -194,7 +199,7 @@ local function onTick(event)
     if (tick == regionMap.processTick) then
 	regionMap.processTick = regionMap.processTick + INTERVAL_PROCESS
 	local surface = game.surfaces[1]
-	local evolutionFactor = game.evolution_factor
+	local evolutionFactor = game.forces.enemy.evolution_factor
 	local players = game.players
 	
 	processPendingChunks(regionMap, surface, pendingChunks)
@@ -245,7 +250,7 @@ local function onDeath(event)
 		    deathScent(deathChunk)
 		    
 		    if ((event.force ~= nil) and (event.force.name == "player")) then
-			local evolutionFactor = game.evolution_factor
+			local evolutionFactor = game.forces.enemy.evolution_factor
 
 			if (deathChunk[MOVEMENT_PHEROMONE] < -(evolutionFactor * RETREAT_MOVEMENT_PHEROMONE_LEVEL)) then
 			    retreatUnits(deathChunk, 
diff --git a/info.json b/info.json
index 451405f..22253c8 100644
--- a/info.json
+++ b/info.json
@@ -1,7 +1,7 @@
 {
     "name" : "Rampant",
-    "factorio_version" : "0.14",
-    "version" : "0.14.13",
+    "factorio_version" : "0.15",
+    "version" : "0.15.1",
     "title" : "Rampant AI",
     "author" : "Veden",
     "homepage" : "https://forums.factorio.com/viewtopic.php?f=94&t=31445",
diff --git a/libs/Constants.lua b/libs/Constants.lua
index 4b6b98e..b5a61cc 100644
--- a/libs/Constants.lua
+++ b/libs/Constants.lua
@@ -11,6 +11,7 @@ constants.VERSION_13 = 13
 constants.VERSION_14 = 14
 constants.VERSION_15 = 15
 constants.VERSION_16 = 16
+constants.VERSION_17 = 17
 
 -- misc
 
diff --git a/prototypes/buildings/tunnel.lua b/prototypes/buildings/tunnel.lua
index a7514b0..0544792 100644
--- a/prototypes/buildings/tunnel.lua
+++ b/prototypes/buildings/tunnel.lua
@@ -9,7 +9,8 @@ data:extend({
     collision_box = {{-1.3, -1.3}, {1.3, 1.3}},
     selection_box = {{-1.5, -1.5}, {1.5, 1.5}},
     render_layer = "remnants",
-    max_health = 0,
+    destructible = "false",
+    max_health = 1,
     pictures =
     {
       {
@@ -20,4 +21,4 @@ data:extend({
       }
     }
   }
-})
\ No newline at end of file
+})
diff --git a/prototypes/enemies/AttackAcidBall.lua b/prototypes/enemies/AttackAcidBall.lua
index f144138..e2d8733 100644
--- a/prototypes/enemies/AttackAcidBall.lua
+++ b/prototypes/enemies/AttackAcidBall.lua
@@ -23,7 +23,7 @@ biterStreamUtils.createBiterStreamAttack(
 				{
 				    {
 					type = "damage",
-					damage = { amount = 7, type = "acid" }
+					damage = { amount = 15, type = "acid" }
 				    }
 				}
 			}
@@ -80,7 +80,7 @@ biterStreamUtils.createBiterStreamAttack(
 			    {
 				{
 				    type = "damage",
-				    damage = { amount = 15, type = "acid" }
+				    damage = { amount = 22, type = "acid" }
 				},
 				{
 				    type= "create-entity",
diff --git a/prototypes/enemies/BiterUtils.lua b/prototypes/enemies/BiterUtils.lua
index a82e35e..4c97155 100644
--- a/prototypes/enemies/BiterUtils.lua
+++ b/prototypes/enemies/BiterUtils.lua
@@ -179,7 +179,7 @@ end
 function biterFunctions.createFireAttack(attributes, fireAttack)
     local attack = {
 	type = "stream",
-	ammo_category = "flame-thrower",
+	ammo_category = "flamethrower",
 	cooldown = attributes.cooldown,
 	range = attributes.range,
 	min_range = attributes.minRange,
@@ -200,7 +200,7 @@ function biterFunctions.createFireAttack(attributes, fireAttack)
 	},
 	ammo_type =
 	    {
-                category = "flame-thrower",
+                category = "flamethrower",
                 action =
 		    {
 			type = "direct",