Before the digital distribution networks, PSN and XBLA, became the showcase for ambitious indie darlings like Braid and Limbo, these cyber storefronts featured a dependable selection of classic arcade titles and addictive puzzlers. In fact, on the day Ed Humphries bought his 360, he logged more time playing the freebie Hexic than he did with the show stopping Call of Duty 2. That’s the beauty of a good puzzle game: if the concept is tight and the execution flawless, the intangible “just one more level” mindset takes root; leaving those speaker-blasting battles to wait another day. Nowadays, the marketplaces are jammed with a vast menagerie of downloadable delights, representing all genres. Where these once bite-sized titles have grown much larger, smaller titles like Mercury Hg exist to tax your brain.