diff --git a/public/Camera.js b/public/Camera.js
index f6985b1..f44c438 100644
--- a/public/Camera.js
+++ b/public/Camera.js
@@ -1,3 +1,5 @@
+"use strict"
+
 export default class Camera {
   constructor() {
     this.x = 0
diff --git a/public/Communication.js b/public/Communication.js
index 7277168..9a5b107 100644
--- a/public/Communication.js
+++ b/public/Communication.js
@@ -1,3 +1,5 @@
+"use strict"
+
 import WsClient from './WsClient.js'
 import Protocol from './../common/Protocol.js'
 
diff --git a/public/Debug.js b/public/Debug.js
index 35c6925..6d8b7c9 100644
--- a/public/Debug.js
+++ b/public/Debug.js
@@ -1,3 +1,5 @@
+"use strict"
+
 import { logger } from '../common/Util.js'
 
 const log = logger('Debug.js')
diff --git a/public/Fireworks.js b/public/Fireworks.js
index 3cda120..3ce3170 100644
--- a/public/Fireworks.js
+++ b/public/Fireworks.js
@@ -1,3 +1,5 @@
+"use strict"
+
 import { Rng } from '../common/Rng.js'
 import Util from '../common/Util.js'
 
diff --git a/public/Graphics.js b/public/Graphics.js
index 1de3863..16a692d 100644
--- a/public/Graphics.js
+++ b/public/Graphics.js
@@ -1,3 +1,5 @@
+"use strict"
+
 function createCanvas(width = 0, height = 0) {
     const c = document.createElement('canvas')
     c.width = width
diff --git a/public/PuzzleGraphics.js b/public/PuzzleGraphics.js
index fd54444..93922ed 100644
--- a/public/PuzzleGraphics.js
+++ b/public/PuzzleGraphics.js
@@ -1,3 +1,5 @@
+"use strict"
+
 import Geometry from '../common/Geometry.js'
 import Graphics from './Graphics.js'
 import Util, { logger } from './../common/Util.js'
diff --git a/public/WsClient.js b/public/WsClient.js
index aff7b59..c01a633 100644
--- a/public/WsClient.js
+++ b/public/WsClient.js
@@ -1,3 +1,5 @@
+"use strict"
+
 import WsWrapper from './WsWrapper.js'
 
 export default class WsClient extends WsWrapper {
diff --git a/public/WsWrapper.js b/public/WsWrapper.js
index 10ead38..f85ddb4 100644
--- a/public/WsWrapper.js
+++ b/public/WsWrapper.js
@@ -1,3 +1,5 @@
+"use strict"
+
 import Time from '../common/Time.js'
 
 /**
diff --git a/public/components/GameTeaser.vue.js b/public/components/GameTeaser.vue.js
index 13369b4..41b198f 100644
--- a/public/components/GameTeaser.vue.js
+++ b/public/components/GameTeaser.vue.js
@@ -1,3 +1,5 @@
+"use strict"
+
 import Time from './../../common/Time.js'
 
 const GameTeaser = {
diff --git a/public/components/ImageTeaser.vue.js b/public/components/ImageTeaser.vue.js
index 90904ee..729c223 100644
--- a/public/components/ImageTeaser.vue.js
+++ b/public/components/ImageTeaser.vue.js
@@ -1,3 +1,5 @@
+"use strict"
+
 const ImageTeaser = {
   name: 'image-teaser',
   props: {
diff --git a/public/components/Upload.vue.js b/public/components/Upload.vue.js
index 8088f2e..83acea0 100644
--- a/public/components/Upload.vue.js
+++ b/public/components/Upload.vue.js
@@ -1,3 +1,5 @@
+"use strict"
+
 const Upload = {
   name: 'upload',
   props: {
diff --git a/public/game.js b/public/game.js
index 46ff2be..ee050f2 100644
--- a/public/game.js
+++ b/public/game.js
@@ -1,4 +1,5 @@
 "use strict"
+
 import {run} from './gameloop.js'
 import Camera from './Camera.js'
 import Graphics from './Graphics.js'
@@ -308,7 +309,6 @@ function addMenuToDom(previewImageUrl) {
 }
 
 function initme() {
-  // return uniqId()
   let ID = localStorage.getItem('ID')
   if (!ID) {
     ID = Util.uniqId()
@@ -399,26 +399,12 @@ function EventAdapter (canvas, window, viewport) {
 
   const createKeyEvents = () => {
     let amount = SHIFT ? 20 : 10
-    let x = 0
-    let y = 0
-    if (UP) {
-      y += amount
-    }
-    if (DOWN) {
-      y -= amount
-    }
-    if (LEFT) {
-      x += amount
-    }
-    if (RIGHT) {
-      x -= amount
-    }
-
+    let x = (LEFT ? amount : 0) - (RIGHT ? amount : 0)
+    let y = (UP ? amount : 0) - (DOWN ? amount : 0)
     if (x !== 0 || y !== 0) {
       addEvent([Protocol.INPUT_EV_MOVE, x, y])
     }
 
-    // zoom keys
     if (ZOOM_IN && ZOOM_OUT) {
       // cancel each other out
     } else if (ZOOM_IN) {
diff --git a/public/gameloop.js b/public/gameloop.js
index 857b9fc..038597a 100644
--- a/public/gameloop.js
+++ b/public/gameloop.js
@@ -1,3 +1,5 @@
+"use strict"
+
 export const run = options => {
   const fps = options.fps || 60
   const slow = options.slow || 1
@@ -28,4 +30,4 @@ export const run = options => {
 
 export default {
   run
-}
\ No newline at end of file
+}
diff --git a/public/views/Index.vue.js b/public/views/Index.vue.js
index 6d4796c..ba73afb 100644
--- a/public/views/Index.vue.js
+++ b/public/views/Index.vue.js
@@ -1,3 +1,5 @@
+"use strict"
+
 import GameCommon from './../../common/GameCommon.js'
 import Time from './../../common/Time.js'
 import Upload from './../components/Upload.vue.js'