Grid Movement script correction

I found this Grid Movement script:
It works perfectly but there is something I would like to change.
When i keep the button to move the player and then I leave it, the player keep moving for some tiles then stops. I want the script more sensible to the keybutton pression, with no delay.
I’m new to scripting and I know very few about C#(I used the one written in C#).
Can somebody help me?

Nothing at all to do with the script; change the input settings for the appropriate axes to get rid of the smoothing (gravity/sensitivity), so that the values return to 0 immediately.