Having just acquired a Sony PSP, I've discovered a new (to me) genre of game.
In both Loco Roco and Mercury Meltdown, you don't directly control a character's movements and actions with the various buttons and joysticks, instead you control the environment that surrounds them. It's by controlling their environment that you indirectly control the character and cause them to move, grab things, expire etc.
In Mercury Meltdown, by tilting floating platforms from side to side, you determine where a shiny blob of mercury rolls. Tilt too much and the blog rolls off the platforms into space - you lose.
In both games the character has no control over its fate - simply rolling passively from one spot to another at the whim and vagaries of its surroundings (the marriage of a 'friend' of mine comes to mind). Whether aware (as in Loco Roco) or not (as in Mercury Meltdown) of their destiny, the main character is manifestly not in charge of it.
These are clearly not user-centric games.