diff --git a/src/net/torvald/terrarum/gameactors/AVKey.kt b/src/net/torvald/terrarum/gameactors/AVKey.kt
index ec446e6ce..8cbdebd92 100644
--- a/src/net/torvald/terrarum/gameactors/AVKey.kt
+++ b/src/net/torvald/terrarum/gameactors/AVKey.kt
@@ -29,7 +29,7 @@ object AVKey {
     const val JUMPPOWER = "jumppower"
     const val JUMPPOWERBUFF = "$JUMPPOWER$BUFF"
 
-    /** How much air jumping you can perform. INT */
+    /** How much air jumping you can perform. 0 is same as 1. INT */
     const val AIRJUMPPOINT = "airjumppoint"
     /** How much air jumping you have performed before you run out of the point. INT */
     const val AIRJUMPCOUNT = "_airjumpcount"
diff --git a/src/net/torvald/terrarum/gameactors/ActorWBMovable.kt b/src/net/torvald/terrarum/gameactors/ActorWBMovable.kt
index eda9aa49a..77b0f9971 100644
--- a/src/net/torvald/terrarum/gameactors/ActorWBMovable.kt
+++ b/src/net/torvald/terrarum/gameactors/ActorWBMovable.kt
@@ -222,9 +222,10 @@ open class ActorWBMovable(renderOrder: RenderOrder, val immobileBody: Boolean =
      * [m / s^2]
      * s^2 = 1/FPS = 1/60 if FPS is targeted to 60
      * meter to pixel : 24/FPS
+     *
+     * NOTE: this property is "var" so that future coder can implement the "reverse gravity potion"
      */
-    private val gravitation: Vector2
-        get() = world?.gravitation ?: Vector2(0.0, 9.8)
+    var gravitation: Vector2 = world?.gravitation ?: GameWorld.DEFAULT_GRAVITATION
     @Transient val DRAG_COEFF_DEFAULT = 1.2
     /** Drag coefficient. Parachutes have much higher value than bare body (1.2) */
     var dragCoefficient: Double
diff --git a/src/net/torvald/terrarum/gameworld/GameWorld.kt b/src/net/torvald/terrarum/gameworld/GameWorld.kt
index a094b07b8..ab18e4287 100644
--- a/src/net/torvald/terrarum/gameworld/GameWorld.kt
+++ b/src/net/torvald/terrarum/gameworld/GameWorld.kt
@@ -83,7 +83,7 @@ open class GameWorld : Disposable {
     //public World physWorld = new World( new Vec2(0, -Terrarum.game.gravitationalAccel) );
     //physics
     /** Meter per second squared. Currently only the downward gravity is supported. No reverse gravity :p */
-    open var gravitation: Vector2 = Vector2(0.0, 9.80665)
+    open var gravitation: Vector2 = DEFAULT_GRAVITATION
     /** 0.0..1.0+ */
     open var globalLight = Cvec(0f, 0f, 0f, 0f)
     open var averageTemperature = 288f // 15 deg celsius; simulates global warming
@@ -490,6 +490,8 @@ open class GameWorld : Disposable {
 
             return nullWorldInstance!!
         }
+
+        val DEFAULT_GRAVITATION = Vector2(0.0, 9.8)
     }
 }
 
diff --git a/src/net/torvald/terrarum/modulebasegame/gameactors/ActorHumanoid.kt b/src/net/torvald/terrarum/modulebasegame/gameactors/ActorHumanoid.kt
index 65e87985e..bf133d44e 100644
--- a/src/net/torvald/terrarum/modulebasegame/gameactors/ActorHumanoid.kt
+++ b/src/net/torvald/terrarum/modulebasegame/gameactors/ActorHumanoid.kt
@@ -162,6 +162,7 @@ open class ActorHumanoid(
     var isLeftDown = false; protected set
     var isRightDown = false; protected set
     var isJumpDown = false; protected set
+    var isJumpJustDown = false; protected set // TODO if jump key is held in current update frame
     protected inline val isGamer: Boolean
         get() = if (Terrarum.ingame == null) false else this == Terrarum.ingame!!.actorNowPlaying
 
@@ -246,6 +247,8 @@ open class ActorHumanoid(
                 isJumpDown = Gdx.input.isKeyPressed(AppLoader.getConfigInt("keyjump")) ||
                              gamepad.getButton(AppLoader.getConfigInt("gamepadltrigger"))
             }
+
+            TODO("isJumpJustDown")
         }
         else {
             isUpDown = axisY < 0f
@@ -347,16 +350,26 @@ open class ActorHumanoid(
         }
 
         /**
-         * Jump control
+         * Jump-key control
          */
         if (isJumpDown) {
             if (!isNoClip) {
+
+                // wall-kick jumps // (think of Mario DS!)
+
+                if (isJumpJustDown && !jumping && (walledLeft || walledRight)) {
+                    printdbg(this, "Wallkicking detection test print")
+                }
+
+                // perpendicular jumps //
+
+                // make airjumping work by resetting some jump-related variables
                 if (!playerJumpKeyHeldDown && (walledBottom || airJumpingCount < airJumpingPoint)) {
                     jumping = true
 
                     // make airjumping work
                     if (airJumpingCount < airJumpingPoint) {
-                        printdbg(this, "airjump!")
+                        //printdbg(this, "airjump!")
                         // reset jumping-related variables
                         jumpCounter = 0
                         airJumpingCount += 1
@@ -365,6 +378,8 @@ open class ActorHumanoid(
                         //controllerV?.y = 0.0
                     }
                 }
+
+                // acutally launch the player in the air
                 jump()
             }
             else {
@@ -434,7 +449,7 @@ open class ActorHumanoid(
         else
             controllerV?.x?.let { controllerV!!.x = controllerV!!.x.plus(readonly_totalX).bipolarClamp(avSpeedCap) }
 
-        if (walkCounterX < 1000000) {
+        if (walkCounterX <= WALK_FRAMES_TO_MAX_ACCEL) {
           walkCounterX += 1
         }
 
diff --git a/src/net/torvald/terrarum/modulebasegame/gameactors/PlayerBuilderTestSubject1.kt b/src/net/torvald/terrarum/modulebasegame/gameactors/PlayerBuilderTestSubject1.kt
index 18f84969a..a00cdd48e 100644
--- a/src/net/torvald/terrarum/modulebasegame/gameactors/PlayerBuilderTestSubject1.kt
+++ b/src/net/torvald/terrarum/modulebasegame/gameactors/PlayerBuilderTestSubject1.kt
@@ -43,7 +43,7 @@ object PlayerBuilderTestSubject1 {
         //p.actorValue[AVKey.LUMB] = 1.37
         //p.actorValue[AVKey.LUMA] = 1.93
 
-        p.actorValue[AVKey.AIRJUMPPOINT] = 2
+        p.actorValue[AVKey.AIRJUMPPOINT] = 0
 
         return p
     }
diff --git a/src/net/torvald/terrarum/ui/BasicDebugInfoWindow.kt b/src/net/torvald/terrarum/ui/BasicDebugInfoWindow.kt
index 5272b3fdf..d2a512f4a 100644
--- a/src/net/torvald/terrarum/ui/BasicDebugInfoWindow.kt
+++ b/src/net/torvald/terrarum/ui/BasicDebugInfoWindow.kt
@@ -131,7 +131,9 @@ class BasicDebugInfoWindow : UICanvas() {
                     "${if (player.walledBottom) "$ccR" else "$ccG"}${0x1F.toChar()}" +
                     "${if (player.walledTop) "$ccR" else "$ccG"}${0x1E.toChar()}" +
                     "${if (player.walledRight) "$ccR" else "$ccG"}R" +
-                    "${if (player.colliding) "$ccR" else "$ccG"}${0x08.toChar()}"
+                    "${if (player.colliding) "$ccR" else "$ccG"}${0x08.toChar()}  " +
+                    "${if (player.jumping) "$ccG" else "$ccK"}JMP" +
+                    "${if (player.isJumpDown) "$ccG" else "$ccK"}KEY"
             )
         }