With some basic playable area prepared, I transitioned into creating a lose state for the player; tracked by their current lives.
The first step was assigning a respawn location; an empty gameobject placed where the player originally spawns when the game starts. They will return here when they die.
As for how they die, the player checks to see if they go below a certain horizontal value. If they do, they lose 1 life and immediately respawn at the beginning