Partly for nostalgia, but definitely on its own merits,The Hacker is my favorite mobile game, so far, of 2012. The first rejected password on that green monochrome screen took me back more than 25 years to Activision's Hacker on the Commodore 64, a game that had no real instruction manual, just that opening screen. LOGON.
The Hacker (99 cents, all iOS platforms) doesn't exactly dump you into the deep end, unprepared, like its spiritual ancestor. Instructions come in the form of communications from colleagues within your hacker collective. The game unfolds into a series of allegorical puzzles for breaking into a network and uncovering the secret of the sinister company that made the "GliderOS." In sum, "The Hacker" is a superbly done alternate reality game for such a small platform.
Once you break into the network you're given a series of puzzles to unlock the next communique from your hacker comrades and resolve the next break-in at one of eight global server locations. The email decryption is a pattern-guessing game; the hacking job involves completing a series of three puzzles. One is like the children's card game "Memory." Another is a movement puzzle where you have to manipulate bug-like icons onto corresponding symbols—every move you make with one icon moves another, unless it's running into a wall. The third is a circuit path puzzle where you create a way toward the objective for your piece of data while avoiding or blocking the network defenses.
All of these games deliver an experience points bonus that can be used to bypass difficult puzzles or, ultimately, unlock minigames that were, in The Hacker's fiction, the games you went looking for when you stumbled into this network and the global conspiracy involving it.
There are many excellent puzzle anthologies available for the iOS platform (I'm thinking of Cross Fingers by Mobigame, and The Heist, which also had an alternate reality payoff). But The Hacker excels by sewing the challenges together with its conspiratorial backstory. Finishing a puzzle is its own reward, but knowing that will unlock more of the story, in such an organic way, motivated me to get through some tough challenges. At 99 cents, it's a great value in the puzzle genre.