Skull Tweak in Bloons TD 6 becomes a serious test of efficiency in Impoppable mode, where bloons are stronger, income is limited, and every decision can affect your ability to survive the later rounds. The map’s skull-shaped layout, water areas, bridges, and line-of-sight blockers make careful tower placement especially important for maximizing coverage and damage. By building a cost-efficient early defense, scaling into powerful mid-game upgrades, and preparing strong late-game MOAB control, you can overcome the increased difficulty and successfully clear all rounds.