diff --git a/bin/parallel-mocha b/bin/parallel-mocha
index 1e4589a..ace88cb 100755
--- a/bin/parallel-mocha
+++ b/bin/parallel-mocha
@@ -1,49 +1,63 @@
 #!/usr/bin/env node
+'use strict';
 
 const program = require('commander');
 const fs = require('fs');
 const glob = require('glob');
 const Runner = require('../lib/runner');
 const async = require('async');
+const chalk = require('chalk');
 
 program
-    .version(JSON.parse(fs.readFileSync(__dirname + '/../package.json', 'utf8')).version)
-    .usage('[options] <files...>')
-    .option('-p, --processes <n>', 'Set number of processes', parseInt)
-    .option('-t, --timeout <n>', 'Timeout between testes', parseInt)
-    .option('-s, --slow <n>', 'Wait for slow tests', parseInt)
-    .parse(process.argv);
-
-// TODO: how can i make sure workers is integer?
+  .version(JSON.parse(fs.readFileSync(__dirname + '/../package.json', 'utf8')).version)
+  .usage('[options] <files...>')
+  .option('-p, --processes <n>', 'Set number of processes', parseInt)
+  .option('-t, --timeout <n>', 'Timeout between testes', parseInt)
+  .option('-s, --slow <n>', 'Wait for slow tests', parseInt)
+  .parse(process.argv);
+
 let processes = program.processes || 20;
 let timeout = program.timeout || 10000;
 let slow = program.slow || 2000;
 let files = program.args;
+let environment = program.environment || 'test';
 
 let resolveFilesQueue = files.map(
-    file=>(cb)=> {
-        glob(file, cb)
-    }
+  file=>(cb)=> {
+    glob(file, cb)
+  }
 );
 
 async.parallel(resolveFilesQueue, (err, files)=> {
-    if (err) {
-        throw err;
-    }
+  if (err) {
+    throw err;
+  }
+
+  files = files.reduce((files, file)=> {
+    return files.concat(file);
+  }, []);
 
-    var runner = new Runner(files, {
-        processes: files.length,
-        timeout: timeout,
-        slow: slow
-    });
-
-    runner.run((error) => {
-        if (error) {
-            console.log('==== Failed: %s', error.message);
-        } else {
-            console.log('==== Pass!');
-        }
-    });
+  var runner = new Runner(files, {
+    processes: files.length,
+    timeout: timeout,
+    slow: slow,
+    env: environment
+  });
+
+  process.stderr.on('data', (data)=> {
+    console.log(chalk.red(data));
+  })
+
+  runner.run((error) => {
+    if (error) {
+      console.log(chalk.red(`Failed: ${error.message}`));
+      // Force epic fail
+      process.exit(1);
+    } else {
+      console.log(chalk.green('All test passed!!'));
+      process.exit(0);
+    }
+  });
 });
 
 
diff --git a/lib/pool.js b/lib/pool.js
index 376126b..eb4a82c 100644
--- a/lib/pool.js
+++ b/lib/pool.js
@@ -1,45 +1,44 @@
-var EventEmitter = require('events').EventEmitter
-  , util = require('util')
-  , DoneCriteria = require('done-criteria')
-  , underscore = require('underscore');
+'use strict';
 
-function Pool(paths, workers) {
-  EventEmitter.call(this);
+const EventEmitter = require('events').EventEmitter;
+const DoneCriteria = require('done-criteria');
+const underscore = require('underscore');
 
-  this.paths = paths;
-  this.workers = workers;
-}
-
-util.inherits(Pool, EventEmitter);
+class Pool extends EventEmitter {
 
-Pool.prototype.start = function() {
-  var self = this
-    , doneCriteria = new DoneCriteria(this.paths, function() {
-        self.emit('done');
-      });
+  constructor(paths, workers) {
+    super(Pool);
+    this.paths = paths;
+    this.workers = workers;
+  }
 
-  self.on('next', function() {
-    self.next(function(path) {
-      doneCriteria.done(path);
+  start() {
+    let doneCriteria = new DoneCriteria(this.paths, () => {
+      this.emit('done');
     });
-  });
-
 
-  underscore.range(this.workers).forEach(function() {
-    self.next(function(path) {
-      doneCriteria.done(path);
-      self.emit('next');
+    this.on('next', ()=> {
+      this.next((path)=> {
+        doneCriteria.done(path);
+      });
     });
-  });
-};
-
-Pool.prototype.next = function(callback) {
-  var path = this.paths.shift();
-  if (path) {
-    this.emit('ready', path, function() {
-      return callback(path);
+
+    underscore.range(this.workers).forEach(()=> {
+      this.next((path)=> {
+        doneCriteria.done(path);
+        this.emit('next');
+      });
     });
+  };
+
+  next(callback) {
+    let path = this.paths.shift();
+    if (path) {
+      this.emit('ready', path, ()=> {
+        return callback(path);
+      });
+    }
   }
-};
+}
 
 module.exports = Pool;
diff --git a/lib/runner.js b/lib/runner.js
index b06db52..8b567a8 100644
--- a/lib/runner.js
+++ b/lib/runner.js
@@ -1,82 +1,73 @@
-var spawn = require('child_process').spawn
-var fs = require('fs')
-var underscore = require('underscore');
+'use strict';
 
-var Pool = require('./pool');
+const spawn = require('child_process').spawn;
+const fs = require('fs');
+const underscore = require('underscore');
 
-function Runner(paths, config) {
+const Pool = require('./pool');
+
+class Runner {
+
+  constructor(paths, config) {
     this.paths = paths;
     this.config = underscore.extend(
-        {
-            bin: ['./node_modules/.bin/mocha']
-            , processes: 2
-        }
-        , config
+      {
+        bin: ['./node_modules/.bin/mocha']
+        , processes: 2
+      }
+      , config
     );
     this.mocha = null;
     this.exitCodes = [];
-}
+  }
 
-Runner.prototype.run = function (callback) {
-    var self = this
-        , pool = new Pool(self.paths, self.config.processes);
+  run(callback) {
+    let pool = new Pool(this.paths, this.config.processes);
+    let exitCodes = [];
 
-    pool.on('done', function () {
-        var success = underscore.every(self.exitCodes, function (code) {
-            return code === 0;
-        });
-        // TODO: return better result rather than just error or not
-        var error = success ? null : new Error('Not all tests passed');
-        return callback(error);
-    });
+    pool.on('ready', (path, callback) => {
+      var args = {
+        path: path,
+        timeout: this.config.timeout,
+        slow: this.config.slow,
+        env: this.config.env
+      };
 
-    pool.on('ready', function (path, callback) {
-        var args = {
-            path: path,
-            timeout: self.config.timeout,
-            slow: self.config.slow
-        };
+      this.spawn(args, (code)=> {
+        exitCodes.push(code);
+        callback();
+      });
+    });
 
-        self.spawn(args, callback);
+    pool.on('done', () => {
+      var success = underscore.every(this.exitCodes, code=>code === 0);
+      var error = success ? null : new Error('Not all tests passed');
+      return callback(error);
     });
+
     pool.start();
-};
+  }
 
-Runner.prototype.spawn = function (args, callback) {
-    var self = this
-        , mocha = self.findMocha()
-        , child = spawn(mocha, [
+  spawn(args, callback) {
+    let mocha = this.findMocha();
+    let child = spawn(mocha, [
         '--timeout', args.timeout,
         '--slow', args.timeout,
         args.path
-    ], {stdio: "inherit", env: underscore.extend(process.env, {NODE_ENV: 'test'})});
-
-    /*child.stdout.once('data', function (data) {
-        process.stdout.write('.');
-        self.exitCodes.push(0);
-        return callback(null);
-    });
-
-    child.stderr.on('data', function (data) {
-        process.stdout.write('%s', data);
-        process.exit();
-    });*/
-
-    child.on('exit', function (code) {
-
-    });
+      ],
+      {stdio: "inherit", env: underscore.extend(process.env, {NODE_ENV: args.env})}
+    );
 
-};
+    child.on('exit', callback);
+  }
 
-Runner.prototype.findMocha = function () {
+  findMocha() {
     if (!this.mocha) {
-        this.mocha = underscore.find(this.config.bin, function (bin) {
-            return fs.existsSync(bin);
-        });
-        this.mocha = this.mocha || 'mocha';
+      this.mocha = underscore.find(this.config.bin, bin =>fs.existsSync(bin));
+      this.mocha = this.mocha || 'mocha';
     }
-
     return this.mocha;
-};
+  }
+}
 
 module.exports = Runner;