I think an innovative idea for a videogame would be one that's extremely realistic. Not so realistic so that your character just walks around, poops and pays taxes, but one in which there are a lot of things that you as the player can't control. For example,
  • After defeating the first enemy, your character becomes guilt-stricken and refuses to move.
  • The character gets addicted to the curative potions you've been feeding him. He goes on a binge during which he consumes the entire stock of them and dies.
  • Wounds don't heal quickly.
  • A neutron bombards your vitals via the gaping hole left in your side from level 5. It transmutates an oxygen atom in your liver, triggering a chain reaction which results in your vaporization.

That game would really suck.