Canabalt creator Adam Saltsman has released Gravity Hook HD ($2.99), an endless, high score-based action title featuring many of the addictive qualities of Saltsman’s previous work.

Equipped with a grappling hook, players ascend an endless vertical shaft by attaching their craft to nearby floating objects. Releasing the hook with precise timing will fling the craft upward.

Many objects are fatal to touch while the grappling hook is attached, however, ensuring a challenging experience as gameplay progresses and grappling opportunities become more precarious.

Gravity Hook HD is available as a universal application for the iPhone and iPad, and also includes the original Gravity Hook title as an unlockable bonus for reaching a 500 meter ascent.

As with Canabalt, the full version of Gravity Hook HD is playable online. As an additional bonus, for this weekend only, Gravity Hook HD’s soundtrack is available as a free download from composer Danny Baranowsky’s Bandcamp site.