what is the difference between the paid and free version of the game?
0.10.5B has more content than 0.9.12B, because the development is done in cycles. we first work on a supporters version which is somewhat like an early access to the future content that gets actively expanded (0.11A -> 0.11B for example). Once this "early access" version is somewhat complete we release it together with the next supporters version when it's ready. For example, when 0.11A releases, current 0.10.5B will become public together with some fixes and additions since it was released for supporters. Then the same will happen to 0.11B when 0.12A releases and so on. Hopefully this is more descriptive
You can check differences in changelog