Could you handle a DS game where the second screen wasn't a mere map or inventory monitor, but an entirely separate adventure?
This trailer for upcoming DS puzzle platformer/shooter Fractured Soul looks pretty bland and dull ... for about fifteen seconds or so. Then it shows the other screen, and my mind begins to hurt.
Many DS games merely use the system's second screen as a convenient menu/map/inventory. Some actively make both screens part of the game - one screen controls what's going on, the other screen displays the action. Fractured Soul takes it a step further by having both screens involved in the action, only it's different action.
From what I can tell from the trailer, Fractured Soul bends the Nintendo standard Light-World-Dark-World concept (or, the Ikaruga Principle, if you would) into rapid-fire time. You can only interact with items and be hurt in the screen of the game that is currently active, but your doppelganger on the other screen repeats all of your actions.
The only trouble is that the two screens feature entirely different levels, and you'll need to be keeping track of both to know if you're switching into safety or just digging yourself a bigger hole.
Ow, my brain.