Grappling Hook is a first-person action puzzle / platform game. You use the Grappling Hook as a mighty high-tech tool to overcome various challenging obstacles by performing incredible moves and fast combinations of daring tricks. The dynamic and surprising levels open opportunities to use the Grappling Hook in unique ways never seen before in a game. Making your way through the levels requires both skill and creativity, while the increasing difficulty pushes you to become a real master of the Grappling Hook.
All this comes together to create an intense, challenging, and rewarding gameplay experience:

• Perform daring moves and tricks with the Grappling Hook.
• Solve challenging gameplay and action puzzles. 
• Beat 31 dynamic, animated, and unique levels. 
• Earn 30 cool achievements and master 248 challenges.
• Create your own levels with the built-in level-editor.

Also available for Mac OS X

Reviews:
"Grappling Hook [..] an incredible first person puzzler/platformer, a title that already is one of the best indie games released this year. [..] the way it is right now – with short but challenging and intense levels, all smartly done, it’s perfect. As a whole, Grappling Hook is an amazing product. It is lighting fast and very challenging, it manages to deliver some really smart puzzles and oblige you act quickly. Or die." 
Calin Ciabai - Unigamesity

"Grappling Hook is a fantastic first-person puzzler which is very much in the same light as Valve's Portal."
Mike Rose - IndieGames.com

"Grappling Hook has many special cues (momentum, reaction speed, acceleration, sound effects, etc.) that make it really satisfying. Only Quake 3 got the first person experience so solid and fun."
Martin Joniki