Playing With Growth and Decay

Hi all. Something I've been dreaming about incorporating into a game (for longer than I've actually been making games) is characters that get weaker over time. Challenging the assumption that "time spent playing = increased effectiveness" has led me to Before WNTR, a solo TTRPG where you play as both a kid who is learning and growing and a robot who is degrading and breaking.

Mechanically, each character is represented during events by a single die. Over time, the kid's die steps up and the robot's die steps down - potentially even breaking down entirely, leaving the kid to act alone.

To keep track of these inverted progressions, the player records the kid's growth through the robot's written log, and records the robot's decay through the kid's changing drawings of the robot.

Is this a concept you've experimented with? Do you have other interesting examples of characters getting weaker over time? The playtest edition of Before WNTR is live here - I'd love to hear if you think the mechanic lands.