Adding mechanics to fix bugs, and trying to use more classic mechanics like health bars.
It turns out that, in software, it is very easy to waste time trying to solve a bug. In most cases the original feature ends up being discarded anyways (especially in game development). So often the best use of your time is not to solve the bug directly, but to continue development. By adding and updating mechanics in your game, you might also find that the original issue was made obsolete. In this case, I attempted to solve the bug of the runaway boulder by making the position of the trap only editable when in "Edit" mode.
Another change that was made was to add health to the Adventurers. The health is set to a random number and the Boulder has a damage number. When the Boulder hits the Adventurer a check is done to see if the player is killed or not. Setting up the health bar has also made me realise that I don't understand the Unity UI system at all. So I'll be spending time watching videos and reading up on that.