Specter Spelunker Shrinks only tells half the story. Yes, pressing down will shrink your spelunking little man, allowing him to venture into passageways that previously only came up to his shin. But pressing up also makes him grow, allowing you to comfortably jump onto that previously towering cliff.
It gets cleverer, too, when you realise that shrinking actually slows down time, and you can morph between sizes in the middle of a jump. It's just brilliant.
Specter Spelunker Shrinks [Gamejolt]