Key bindings refer to the specific actions assigned to certain keys on a keyboard. It determines how pressing a particular key will produce a specific result or perform a certain function in a computer program or application. Full definition
Single - player only: implemented auto - attack with mouse and keyboard controls, with a new key binding created for this purpose. (gamingtrend.com)
Lack of key bindings on the keyboard, however, might be something implemented in a patch down the line if the demand is large enough. (tinimations.net)
The pacing is off, the story is unmemorable, there's a feeling of loneliness throughout the entire game created by Bungie's lack of desire for any social interaction, no matchmaking, no ranked multiplayer (multiplayer is lacking in so many features it feels more like a demo than an actual release), game - ruining bugs like inability to change key bindings. (metacritic.com)