gistfile1.js

// the game's canvas element
var canvas = null;
// the canvas 2d context
var ctx = null;
// an image containing all sprites
var spritesheet = null;
// true when the spritesheet has been downloaded
var spritesheetLoaded = false;

// the world grid: a 2d array of tiles
var world = [[]];

// size in the world in sprite tiles
var worldWidth = 16;
var worldHeight = 16;

// size of a tile in pixels
var tileWidth = 32;
var tileHeight = 32;

// start and end of path
var pathStart = [worldWidth,worldHeight];
var pathEnd = [0,0];
var currentPath = [];

// ensure that concole.log doesn't cause errors
if (typeof console == "undefined") var console = { log: function() {} };

There is a small typo at line 26, "concole.log"