If you really want to do this achievement, I recommend you to memorize every levels first before actually attempting it. I'm just gonna go straight to the point, so let's get it done.

1. Firstly, we need to open regedit.exe so the fastest way is to press "Windows + R" on your keyboard and type "regedit" on the given box and click OK.



2. Next, we need to find the save file location on regedit, so go to this directory, "Computer\HKEY_CURRENT_USER\Software\Tayfun Zeytun\Instant Death" and you should see something like this:



3. Right click on the folder "Instant Death" and click "Export" if you want to backup your save file first and save it to wherever your want, then click "Delete" to delete your save file and click Yes.





There you have it, you have successfully reset your game data! You can now try to get the "God" achievement and hopefully this time, you will get it! If you still don't understand on how to delete your save file, don't worry, you can follow this video that I did here:


Cheers!

Also, if you want to see all of the levels, you can check out my video here: