You can move the ~/Kobold2D folder after installation to wherever you want.

There's only one thing to consider: for the Kobold2D Project Upgrader tool to work every versioned Kobold2D folder (eg. /Kobold2D-1.0) should be in the same folder, so that the folder structure looks something like this:

Otherwise the Kobold2D Project Upgrader tool won't be able to find upgradeable Kobold2D Projects.

The Kobold2D installer doesn't allow you to install Kobold2D to a different folder. It will always install Kobold2D to ~/Kobold2D. This is done so that users without a system administrator account can install Kobold2D.