https://docs.unity3d.com/6000.4/Documentation/ScriptReference/Input.GetKeyDown.html
Unity - Scripting API: Input.GetKeyDown
scripting apiunityinput
https://discussions.unity.com/t/getkeydown-reacts-more-than-once/18033
GetKeyDown reacts more than once! - Questions & Answers - Unity Discussions
Apr 1, 2011 - I have a ChatLikeExample. If I press enter the text inside the textfield will be send. My problem is, that GetKeyDown reacts more than once (exactly 4 times),...
more than oncequestions answersreactsunitydiscussions
https://docs.unity3d.com/es/2017.2/ScriptReference/Input.GetKeyDown.html
Input-GetKeyDown - Unity Scripting API
Devuelve true durante el frame que el usuario empieza a presionar la tecla identificada por name.
inputunityscriptingapi