Can durandal gulp file size be smaller and how to achieve that?

Question

Recently i started using gulp for optimization, The generated file is just huge around 2.6 MB with gzip it gets chunked to 397 KB which is still big for my taste, The thing is the project is not near finished and it will only get bigger, Any advice would be great, Please help.

I uploaded the generated file in case you want to have a look at it

Generated File by Gulp

Also here's the code i used, Just followed the tutorial not much

var gulp = require('gulp');

var durandal = require('gulp-durandal');

gulp.task('default', function () {
    return durandal({
        baseDir: 'app',
        main: 'main.js',
        output: 'main-gulp.js',
        almond: true,
        minify: true
    }).pipe(gulp.dest('../'));
});