For the past week, I've been focusing on improving the game feel:

• Added sounds to grappling hook
• Rope and grappling hook are now rendered as something more interesting than just a red dot
• The backpack bounces a tiny bit... although I'm not sure if this made any difference
• Made the game a bit faster overall
• Tweaked  the level and grace parameters to make the game a bit more forgiving and less annoying

The next thing to focus on will probably be the level design. Currently, the biggest problem with it is that it's too short. I'm slightly worried that the gameplay mechanics that I've implemented aren't varied enough for a longer level, but we'll see.

Cheers!