Hello,
We just shipped the Authoring tools that were also used crafting the game. It also includes source assets.
You can find it here: http://store.steampowered.com/app/750430/Sphinx_and_the_Cursed_Mummy_Authoring_Tools/
Please be aware that you need to tell Steam to download it.
We prepared a guide here on how to set it up and first steps with it: http://steamcommunity.com/sharedfiles/filedetails/?id=1306820082
Enjoy!