diff --git a/.idea/modules/kudens.iml b/.idea/modules/kudens.iml
index bcffa19..1a18df3 100644
--- a/.idea/modules/kudens.iml
+++ b/.idea/modules/kudens.iml
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<module external.linked.project.id="kudens" external.linked.project.path="$MODULE_DIR$/../.." external.root.project.path="$MODULE_DIR$/../.." external.system.id="GRADLE" external.system.module.group="perses.games" external.system.module.version="1.1.2-SNAPSHOT" type="JAVA_MODULE" version="4">
+<module external.linked.project.id="kudens" external.linked.project.path="$MODULE_DIR$/../.." external.root.project.path="$MODULE_DIR$/../.." external.system.id="GRADLE" external.system.module.group="perses.games" external.system.module.version="1.1.3-SNAPSHOT" type="JAVA_MODULE" version="4">
   <component name="FacetManager">
     <facet type="kotlin-language" name="Kotlin">
       <configuration version="2" platform="JavaScript " useProjectSettings="false">

diff --git a/.idea/modules/kudens.iml b/.idea/modules/kudens.iml
index bcffa19..1a18df3 100644
--- a/.idea/modules/kudens.iml
+++ b/.idea/modules/kudens.iml
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<module external.linked.project.id="kudens" external.linked.project.path="$MODULE_DIR$/../.." external.root.project.path="$MODULE_DIR$/../.." external.system.id="GRADLE" external.system.module.group="perses.games" external.system.module.version="1.1.2-SNAPSHOT" type="JAVA_MODULE" version="4">
+<module external.linked.project.id="kudens" external.linked.project.path="$MODULE_DIR$/../.." external.root.project.path="$MODULE_DIR$/../.." external.system.id="GRADLE" external.system.module.group="perses.games" external.system.module.version="1.1.3-SNAPSHOT" type="JAVA_MODULE" version="4">
   <component name="FacetManager">
     <facet type="kotlin-language" name="Kotlin">
       <configuration version="2" platform="JavaScript " useProjectSettings="false">
diff --git a/.idea/modules/kudens_main.iml b/.idea/modules/kudens_main.iml
index e9cef24..0c9cf9b 100644
--- a/.idea/modules/kudens_main.iml
+++ b/.idea/modules/kudens_main.iml
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<module external.linked.project.id="kudens:main" external.linked.project.path="$MODULE_DIR$/../.." external.root.project.path="$MODULE_DIR$/../.." external.system.id="GRADLE" external.system.module.group="perses.games" external.system.module.type="sourceSet" external.system.module.version="1.1.2-SNAPSHOT" type="JAVA_MODULE" version="4">
+<module external.linked.project.id="kudens:main" external.linked.project.path="$MODULE_DIR$/../.." external.root.project.path="$MODULE_DIR$/../.." external.system.id="GRADLE" external.system.module.group="perses.games" external.system.module.type="sourceSet" external.system.module.version="1.1.3-SNAPSHOT" type="JAVA_MODULE" version="4">
   <component name="FacetManager">
     <facet type="kotlin-language" name="Kotlin">
       <configuration version="2" platform="JavaScript " useProjectSettings="false">

diff --git a/.idea/modules/kudens.iml b/.idea/modules/kudens.iml
index bcffa19..1a18df3 100644
--- a/.idea/modules/kudens.iml
+++ b/.idea/modules/kudens.iml
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<module external.linked.project.id="kudens" external.linked.project.path="$MODULE_DIR$/../.." external.root.project.path="$MODULE_DIR$/../.." external.system.id="GRADLE" external.system.module.group="perses.games" external.system.module.version="1.1.2-SNAPSHOT" type="JAVA_MODULE" version="4">
+<module external.linked.project.id="kudens" external.linked.project.path="$MODULE_DIR$/../.." external.root.project.path="$MODULE_DIR$/../.." external.system.id="GRADLE" external.system.module.group="perses.games" external.system.module.version="1.1.3-SNAPSHOT" type="JAVA_MODULE" version="4">
   <component name="FacetManager">
     <facet type="kotlin-language" name="Kotlin">
       <configuration version="2" platform="JavaScript " useProjectSettings="false">
diff --git a/.idea/modules/kudens_main.iml b/.idea/modules/kudens_main.iml
index e9cef24..0c9cf9b 100644
--- a/.idea/modules/kudens_main.iml
+++ b/.idea/modules/kudens_main.iml
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<module external.linked.project.id="kudens:main" external.linked.project.path="$MODULE_DIR$/../.." external.root.project.path="$MODULE_DIR$/../.." external.system.id="GRADLE" external.system.module.group="perses.games" external.system.module.type="sourceSet" external.system.module.version="1.1.2-SNAPSHOT" type="JAVA_MODULE" version="4">
+<module external.linked.project.id="kudens:main" external.linked.project.path="$MODULE_DIR$/../.." external.root.project.path="$MODULE_DIR$/../.." external.system.id="GRADLE" external.system.module.group="perses.games" external.system.module.type="sourceSet" external.system.module.version="1.1.3-SNAPSHOT" type="JAVA_MODULE" version="4">
   <component name="FacetManager">
     <facet type="kotlin-language" name="Kotlin">
       <configuration version="2" platform="JavaScript " useProjectSettings="false">
diff --git a/.idea/modules/kudens_test.iml b/.idea/modules/kudens_test.iml
index a735c3a..d34714c 100644
--- a/.idea/modules/kudens_test.iml
+++ b/.idea/modules/kudens_test.iml
@@ -1,22 +1,18 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<module external.linked.project.id="kudens:test" external.linked.project.path="$MODULE_DIR$/../.." external.root.project.path="$MODULE_DIR$/../.." external.system.id="GRADLE" external.system.module.group="perses.games" external.system.module.type="sourceSet" external.system.module.version="1.1.2-SNAPSHOT" type="JAVA_MODULE" version="4">
+<module external.linked.project.id="kudens:test" external.linked.project.path="$MODULE_DIR$/../.." external.root.project.path="$MODULE_DIR$/../.." external.system.id="GRADLE" external.system.module.group="perses.games" external.system.module.type="sourceSet" external.system.module.version="1.1.3-SNAPSHOT" type="JAVA_MODULE" version="4">
   <component name="FacetManager">
     <facet type="kotlin-language" name="Kotlin">
       <configuration version="2" platform="JavaScript " useProjectSettings="false">
-        <compilerSettings>
-          <option name="additionalArguments" value="-verbose" />
-        </compilerSettings>
+        <compilerSettings />
         <compilerArguments>
-          <option name="outputFile" value="$MODULE_DIR$/../../build/kotlinjs/kudens.js" />
+          <option name="outputFile" value="$MODULE_DIR$/../../build/classes/test/kudens_test.js" />
           <option name="noStdlib" value="true" />
-          <option name="sourceMap" value="true" />
           <option name="metaInfo" value="true" />
           <option name="target" value="v5" />
           <option name="moduleKind" value="plain" />
           <option name="main" value="call" />
           <option name="languageVersion" value="1.1" />
           <option name="apiVersion" value="1.1" />
-          <option name="suppressWarnings" value="true" />
           <option name="pluginClasspaths">
             <array />
           </option>

diff --git a/.idea/modules/kudens.iml b/.idea/modules/kudens.iml
index bcffa19..1a18df3 100644
--- a/.idea/modules/kudens.iml
+++ b/.idea/modules/kudens.iml
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<module external.linked.project.id="kudens" external.linked.project.path="$MODULE_DIR$/../.." external.root.project.path="$MODULE_DIR$/../.." external.system.id="GRADLE" external.system.module.group="perses.games" external.system.module.version="1.1.2-SNAPSHOT" type="JAVA_MODULE" version="4">
+<module external.linked.project.id="kudens" external.linked.project.path="$MODULE_DIR$/../.." external.root.project.path="$MODULE_DIR$/../.." external.system.id="GRADLE" external.system.module.group="perses.games" external.system.module.version="1.1.3-SNAPSHOT" type="JAVA_MODULE" version="4">
   <component name="FacetManager">
     <facet type="kotlin-language" name="Kotlin">
       <configuration version="2" platform="JavaScript " useProjectSettings="false">
diff --git a/.idea/modules/kudens_main.iml b/.idea/modules/kudens_main.iml
index e9cef24..0c9cf9b 100644
--- a/.idea/modules/kudens_main.iml
+++ b/.idea/modules/kudens_main.iml
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<module external.linked.project.id="kudens:main" external.linked.project.path="$MODULE_DIR$/../.." external.root.project.path="$MODULE_DIR$/../.." external.system.id="GRADLE" external.system.module.group="perses.games" external.system.module.type="sourceSet" external.system.module.version="1.1.2-SNAPSHOT" type="JAVA_MODULE" version="4">
+<module external.linked.project.id="kudens:main" external.linked.project.path="$MODULE_DIR$/../.." external.root.project.path="$MODULE_DIR$/../.." external.system.id="GRADLE" external.system.module.group="perses.games" external.system.module.type="sourceSet" external.system.module.version="1.1.3-SNAPSHOT" type="JAVA_MODULE" version="4">
   <component name="FacetManager">
     <facet type="kotlin-language" name="Kotlin">
       <configuration version="2" platform="JavaScript " useProjectSettings="false">
diff --git a/.idea/modules/kudens_test.iml b/.idea/modules/kudens_test.iml
index a735c3a..d34714c 100644
--- a/.idea/modules/kudens_test.iml
+++ b/.idea/modules/kudens_test.iml
@@ -1,22 +1,18 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<module external.linked.project.id="kudens:test" external.linked.project.path="$MODULE_DIR$/../.." external.root.project.path="$MODULE_DIR$/../.." external.system.id="GRADLE" external.system.module.group="perses.games" external.system.module.type="sourceSet" external.system.module.version="1.1.2-SNAPSHOT" type="JAVA_MODULE" version="4">
+<module external.linked.project.id="kudens:test" external.linked.project.path="$MODULE_DIR$/../.." external.root.project.path="$MODULE_DIR$/../.." external.system.id="GRADLE" external.system.module.group="perses.games" external.system.module.type="sourceSet" external.system.module.version="1.1.3-SNAPSHOT" type="JAVA_MODULE" version="4">
   <component name="FacetManager">
     <facet type="kotlin-language" name="Kotlin">
       <configuration version="2" platform="JavaScript " useProjectSettings="false">
-        <compilerSettings>
-          <option name="additionalArguments" value="-verbose" />
-        </compilerSettings>
+        <compilerSettings />
         <compilerArguments>
-          <option name="outputFile" value="$MODULE_DIR$/../../build/kotlinjs/kudens.js" />
+          <option name="outputFile" value="$MODULE_DIR$/../../build/classes/test/kudens_test.js" />
           <option name="noStdlib" value="true" />
-          <option name="sourceMap" value="true" />
           <option name="metaInfo" value="true" />
           <option name="target" value="v5" />
           <option name="moduleKind" value="plain" />
           <option name="main" value="call" />
           <option name="languageVersion" value="1.1" />
           <option name="apiVersion" value="1.1" />
-          <option name="suppressWarnings" value="true" />
           <option name="pluginClasspaths">
             <array />
           </option>
diff --git a/src/main/kotlin/games/perses/game/Game.kt b/src/main/kotlin/games/perses/game/Game.kt
index d563e44..3d80012 100644
--- a/src/main/kotlin/games/perses/game/Game.kt
+++ b/src/main/kotlin/games/perses/game/Game.kt
@@ -88,6 +88,24 @@
     var borderLeft = 0
     var borderTop = 0
 
+    var focus = true
+
+    init {
+        window.onfocus = {
+            println("GOT FOCUS!")
+
+            focus = true
+            ""
+        }
+        window.onblur = {
+            println("LOST FOCUS!")
+
+            focus = false
+            ""
+        }
+
+    }
+
     fun gl() = html.webgl
 
     fun resize() {
@@ -185,7 +203,10 @@
                         fpsCount = 0
                     }
 
-                    currentScreen.update(timeInSeconds.toFloat(), currentDelta)
+                    if (focus) {
+                        currentScreen.update(timeInSeconds.toFloat(), currentDelta)
+                    }
+
                     currentScreen.render()
                 }
             }