I'm genuinely surprised this won, it's actually not such a horrible theme. It's basically a game design principle, so it's widely applicable, which for LD themes is quite rare. I can see a lot of diverse games coming out of this.

Off the top of my head, some games that make use of this mechanic:

Tetris

Snake

Uno

Tower Bloxx

Some specific uses of the mechanic:

Nemesis from Cave Story (powerful weapon that gets weaker as you collect XP)

Equalizer from Team Fortress 2 (weapon that does less damage at full health, but more damage at low health)