using old game data?

Is there any way to allow the game to check and see if a game has already been played (beaten or not) and load the data for the beggining of a new game... for example, you play the game, win, and go to start a new game, you get all the items, and levels that you earned in the first game, but starting from the beggining again....  or (because of the way I'm setting it up) when you die, you still have the levels, but lose your items, and you have to start over.....

At the end, put everything like it was at beginning of the game, with the modifacations you want.

Switches and variables.

When you want them to start over, move them to the starting postion and switch off all the switches and variables.