I also tried your new prototype and think the grappling hook and ledge grab are two great new additions. I wonder if adding the mouse would make controlling the grappling hook or other abilities easier. As it is now the right hand only controls ducking and grappling hook. Maybe the mouse cursor position could be a "target" for the grappling hook and a left click could fire it. I'm thinking down the road, a right click of the mouse could bring up a local menu by the cursor with a list of abilities to select from (superjump, invisibility, superstrength, etc). A simple left click over the desired ability in the list would ready it, and subsequent left clicks would use that ability. What do you think?
