Welcome to this week’s second edition of iPhone Gems, which looks at two retro-inspired games from different developers. First up is Space Miner: Space Ore Bust, which evolves the classic 1979 Atari arcade game Asteroids into a deeper and non-linear shooting adventure, followed by Giana Sisters, a clone of Nintendo’s beloved 1985 run-and-jump title Super Mario Bros. Both of these games will attract fans due to the original subject matter,…