Even though it never really worked out, Darius Force tried to add some new gameplay elements, which reflected other classical horizontal shoot'em ups. There was more avoidance of crashing into scenery(never entirely absent in Darius games, but enemies crashing into you was more important), some fancy rotation of the area of play to include upward and downward scrolling, and a few fast-scrolling sections where one had to watch out for one's head. Zone F had a bit of some of these, and of course, at the end of the stage, this grey shell comes whirling around, making it feel like the outro to "Hangar 18".
Tips: So, in an utter travesty of known biology, the shell and body of the snail come in from the top and bottom of the screen (respectively), and start things off. The shell, with five very visible holes, fires bullets from them in a spiral, and then takes off, spinning as usual, to be mean to you. At the same time, the body of the snail fires some (three, to be precise) missiles at you. The shell can be destroyed, and one must concentrate on the body to take the thing out. The missile launcher will eventually blow up, too, leaving a little orb thingy. I think it fires out some bullet arcs but I can't remember as of now. But he's far gone by now, so cheer up.
