@Dasts; True, and it does take some figuring out how to place them appropriately, but one or two of them placed well along with a blade tower seriously destroys. =D At best you'll only need one or two of those spike-o-pults in any level once you know how to place them. Thankfully they can't pop frozen bloons or else they'd truly be overpowered. ;p
Red bloon = 1hp Blue bloon = 2hp Green bloon = 3hp Yellow bloon = 4hp Black and White bloon = 9hp All towers, ignoring the ice tower, deal 1HP. Strategy? Yes, very little, I won't argue. But knock it off with the "No HP" commentary! >_<