Hi mikeshatter and welcome
Quote: "restarts the mission on death, so you don't respawn "
First, just so we know, which version of fpsc are you using? Sometimes it makes a difference.
To answer your question it's really easy, try this, when placing your player start marker, right click on it, set player lives to 1 (one)..that's it!
Now build your game, test it out, player should have only 1 life. When player dies...game over. But you asked to "restart" the mission.
This involves a little scripting. If you just want to "restart" from level 1, then the command "newgame" is what you would use. But to
start on the same level from the beginning one would need to do a "quicksavegame" at the very start, then when player dies
use "quitegame" & "quickloadgame" .... this would load last saved game in slot-1. For more on this please start a new thread in the "Scripting" forum
and ask away
In the mean time, here are a few links to some really great info to help you get started.
Scrpting info...
https://forum.thegamecreators.com/thread/192148
The Syntax list...
https://forum.thegamecreators.com/thread/180924
Also look in your "doc's" folder. The ocfpscguide.pdf is a great manual to read over. Loaded with many answers to questions

Best,
My games never have bugs. They just develop random features..
Lots and lots of random features...