Nearly a year before they put out 2009's surprise Flash/iPhone hit Canabalt, Adam "Saltsman" Atomic and composer Danny Baranowsky worked together on another one-button game, Gravity Hook. Created in just five days, the simple but addictive Flash game had players ascending a mine by throwing a grappling hook onto floating orbs, then pulling themselves toward the orb and using their momentum to reach the next orb.

Adam and Danny have returned to the project -- their first collaboration -- to add new graphics, sound, controls, and gameplay to the game while still keeping its one-button simplicity, and released it as Gravity Hook HD. They're planning to release a paid version for iPhone and iPod Touch, but as with Canabalt, you can play the full title for free online.

I've already lost an hour to it, and it's just as habit-forming as the original. To make it even worse for fans of the original version, the two promise a special treat if you can reach the 500m mark; so, don't plan to eat dinner any time soon if that's the goal you're shooting for. Even with the changes to make the game more approachable, like cutting back on the exploding orbs, dying is still ridiculously easy in Gravity Hook HD.