The release is the whole game. Saves from older versions will not be compatible with the new release.
While waiting for your download to complete, delete all game files for Demon Deals already on your computer - if you have any.
After the download is finished, unzip into a game folder.
Run the EXE.
If you have never played the game before, start a new game. When the save option opens up every in-game morning (or anytime it pops up), save your progress in a new save slot (or rotate through 3-7 save slots).
If you have played to the end of v0.4.1, then continue the game by opening up the provided save in slot #50.