If you're updating to version 1.660, all your save game progress are lost because we're adding lots of new data structure. Now that version 1.660 has stable data structure, updating to new version will not overwrite your save game progress.
As a matter of fact, we will push update version 1.670 soon as we found nasty game breaking bugs. If you have version 1.660, updating to version 1.670 will not overwrite your save game progress.