Ben 10 - Underworld

You control Ben Tennyson, moving left and right through a series of platforming levels. Your main goal is to fight through the Underworld to rescue Gwen. Moment to moment, you're running, jumping across gaps, and using the spacebar to fire energy blasts at the various enemies that appear. The levels are linear, pushing you forward through different themed areas. The pacing is fairly quick, and the challenge comes from timing your jumps and managing the enemies that swarm you. It feels like a brisk, no-nonsense arcade run.