Welcome to this week’s second gaming edition of iPhone + iPad Gems, featuring two universal games, one that has separate versions for iPad and iPhone/iPod touch, and an iPhone-only title. Of the bunch, Mega Mall Story is our favorite; it’s an addicting simulation game with pixel art. Read on for all the details. Cado Of the four games being reviewed here today, Cado ($1, version 1.0) from ClearCut Games is the most basic in terms of…