HoMM3 HD is a mod (add-on) for the game Heroes of Might and Magic 3.

Regarding the market, it could be added (if there's an option to disable it online, it doesn't make much sense).
I would suggest limiting autosaves to 3 (which would overwrite each other, like in Heroes of Might and Magic V). Otherwise, it could clutter the entire save folder, and it might take a while to find something there.
In any case, if there's an option to disable any feature (not everyone needs everything), then any improvements can be made.