The lives system is very old-school. Its not something you commonly see anymore in the past 10 years with games. In fact with a first person shooter its something I dont recall being in any game I've played a part from an arcade style game 20 years ago.
In FPSC and other engines, from what i recall, I would handle this by creating a save state every time the player enters a new level. When the player dies it loads that previous save state. Save state being somewhat different from a player's manual save.
Here is a list of all the different types you can find in games.
Its a complex problem to deal with for those that want more modernized style of play. I also personally feel the immersion in the game is broken when you have moved something or collected something or killed something and when you die, those objects and variables are not repositioned nor reset to their original state.
Simple answer is using save and load states in scripting. Not sure if this is supported with GG as I've not gotten that far into my game yet. But since I've been working on an RPG... this is going to be a critical component.