Say you have a UI button, clicking it increases the speed of your character by 10% if you have enough in-game currency. After obtaining it, I want it to be still available at an increased cost and increment it's effectiveness by 10% on each click. The only way I could think of is if you had a the button take you to a new world with new settings, but doing it that way would require waaaaaay too many worlds if you have multiple upgrades that effect different attributes of the character. It would lead to a nightmare spiderweb-like mind map and it wouldn't be unlimited. There would have to be a top tier world where everything is maxed out.
