Vim mode on pause menu

screen_main.go

@@ -16,7 +16,6 @@ const (
 	modeRun
 	modeRunInput
 	modePause
-	modeGameOver
 )
 
 type mainScreen struct {
@@ -129,6 +128,7 @@ func (screen *mainScreen) performLayout(style style) {
 			(ScreenWidth/2)-11, (ScreenHeight/2)-3, 22, 6,
 			style.defaultFg, style.defaultBg)
 		screen.PauseMenu.SetBordered(true)
+		screen.PauseMenu.EnableVimMode()
 		screen.GameMode = modeRun
 	}
 }