Well... Categorically, the Burj Khalifa is the tallest structure in the entire world. Mount Everest is the tallest mountain.
You can't take the theme as 100% literal, or you'll put limits on your own imagination. "All else" is an intentionally vague concept. "All else" of what? All other trees? All other monsters? All other houses of cards?
Perhaps you could make a game about a giant towering above all that surrounds it, crushing things beneath his feet. Or two players racing to make the tallest structure. Or fighting your way up a monolithic tower in a fantasy RPG. The possibilities are broad here.