Here are some detective/mystery games/VN's I thought I could mention:
  • Jake Hunter Detective Story: Memories of the Past (DS, $15)
  • Jake Hunter: Detective Chronicles (DS, $15)
  • Ghost Trick: Phantom Detective (DS, $20, technically not a visual novel, by the creator of the Ace Attorney series)
  • Chase: Cold Case Investigations ~Distant Memories~ (3DS, $6, download-only, short)
  • Parascientific Escape ～Cruise in the distant seas～ (3DS, $5, download-only, free demo available)
  • Parascientific Escape ～Gear Detective～ (3DS, $5, download-only)
  • Parascientific Escape ～Crossing at the Farthest Horizon～ (3DS, $5, download-only)