For Tetris DS, is this actually a demo or an NFR? If it is not a demo it should go into the main game category. If it is a demo, it doesn't need "Not for Resale" descriptor but that should be in the alt-name.
For the Pokemon item, it is considered "software" and should be in the games category.
But I will say that non-game media for consoles is not really concise on where those items go. Like, what allows an item to be in a game category and not the accessory category? I'm thinking about other things that are in either, like media adapter discs (Game Boy player, Saturn VCD, etc) or Car License and the like. Certainly not things like RAM/ROM carts or Everdrive type things which are clearly accessories.