Certainly the most appealing feature for me was the grappling hook and rope combo -- one of many features cloned from Liero -- which allowed for humiliating, Tarzan-like, bombing raids against unsuspecting brothers and sisters.
At the time, the state-of-the-art means for clearing a cave was to tie a rope around the waist of an infantryman, who would crawl in and toss ahead a grappling hook to probe for mines or booby traps.