Skull Tweak in Bloons TD 6 becomes much more unpredictable in Alternate Bloons Rounds mode, where bloon types and round compositions differ from the standard progression. The map’s skull-shaped layout, water areas, bridges, and line-of-sight blockers make adapting your defense even more important, as the best placements and tower combinations may change depending on the threats you face. By building a flexible defense with reliable damage, strong utility, and efficient coverage, you can handle unexpected bloon waves and successfully clear every round.