Creating a menu while categorizing my products
You can use Superfish to replace the default main menu that comes with commerce kickstart, however you use it at a cost since this jquery drop down menus are usually not optimized for mobile, although superfish provides some optimizations (most in a beta state right now).

Anyway if you need a big dropdown menu your alternatives are short, and Superfish provides minimal mobile browser support if used with a responsive theme (auto-resize and support for touch devices).