First off, let me say that this game is awesome.  I spend way more time than I should playing it.  I have been working on all the unlockable art/animations and enjoying the various outcomes with encounters. 

So basically, I really want to get the story mode.  I don't really want to start all my achievements over.   If I get it, will it install as an update, or do I have to redo everything? 

It's absolutely the same version with unlocked content, so it will be the same as updating the usual game.

If you ever feel your achievements are not safe, you can press Load and Go to files folder. You'll see where your profile.json file is located, it had all achievements and gallery saved. So you can copy it.

Though achievements don't work inside Story mode 😁

So, I did subscribe to patreon.   I don't know if majalis will see this, but 0 regrets.  This game is hot, and so well done.  Love the constant updates.   Please keep feeding us great content!  Oh, and with latest update, thanks for making mages great again!