Tremors, but a game. You are a big sand worm, like the slithering giant in Dune, and your goal is to eat the poor folk of Egypt and their camels (or another applicable country). Then you grow. You eat their jeeps. Their soldiers. Their helicopters. Death Worm is the straightforward game of ye olde Centipede made into something twice as vicious, but just as simple.
There is grace in the snaking movement of this big boy. You drill through the earth and rock as if swimming, and leap out of it like a Great White Shark snapping at your prey. You can bob up and down along the surface like some terrifying dolphin, and scare people into running the opposite direction by leaping out of the earth in front of them. A big, slidey monster.
Like all things simple and strong, it inspired others. There was Worm Food, pretty much a spiritual successor, and there was Pequod in which the soil worm became a salty whale. I remember the first game in its Flash form best (although the one linked there is a dolled-up version), and it has since been squashed into telephones. Do the children of today still indulge the godly annelid horror? I hope so. To forget the Death Worm beneath our feet would be unwise.