Oh, I really like that idea! I personally thought of linking more different statistics originally, like constraining an enemy to a certain height based on for example your health, something like that.
As for the bug, it's a known one and is fixed already in the fixed version of the game I linked in the description, that was caused due to the game over screen referencing the wrong background (two levels always share the same background, so the background ID is half of the level ID rounded down; and the game over screen tried the level ID directly); which you can actively see when dying to the mad scientist (level 2).