You now hafta dig it up or blow them out, or both. See, Dug has this hose that you can stick inside enemies and inflate them until they pop. He also has a jackhammer. When you destroy all monsters on an island, you go to the next place to eliminate more hellspawn. This game just repeats after you beat it anyways, so you don't need to save it.
Fruit pops up every once in awhile.
Fruit gives you points. Fruit is nutritious. If you get enough points, you get an extra life, like many arcade games. First, let's get the side streets outta the way. The same tune repeats over and over, so fortunately it's gonna be drowned out by the sounds of monsters exploding and islands crumbling.