More like omitted feature, but well…
In most applications, when you press Enter while in single-line edit control or other place where using enter makes little sense, the OK button is “pressed”. When you press ESC, action associated with Cancel is used. That is not case with GD. here you need to move hand over to mouse and move cursor to OK/Cancel button which makes you lose precious time (especially if you’re doing LD game). When you press enter/esc you only hear that annoying ding sound.