This is a very nice concept but unfortunately it lacks some things.

First of all, it lacks a 3D skybox. If you add it you will increase the detail and looks of the map dramatically since you will actually make good use of the environment.

Secondly you need to improve the lightning in the inside of the dirigible by actually adding some light entities.

And finally, you need to use some brighter texture for the balloon. A good thing would be to stretch the balloon's texture much more so it looks less repetitive.

Good job. I hope you add the 3D skybox.

This looks great! Nice work!