I have added a parameter for the delay after the tiles have spun in but before they slide:
--initial_delay : 1.5; /* Delay (in seconds) after tiles appear but before they start to slide */
Regarding the othertiming I’m a little adverse to yet another parameter. It is very easy though to change the code. The animation part of the code is relatively simple - this is the whole of it (line 390 onwards):
tl_1.set('.tile', {scale : 0, rotationX: 360, rotationY: 360, rotationZ: 360}, '>');
tl_1.to ('.tile', {scale : 1, rotationX: 0, rotationY: 0, rotationZ: 0, duration: 10 * P.animation_duration.value}, `>${P.animation_delay.value}`);
tl_1.set({}, {}, P.initial_delay.value);
slider.reverse_play();
tl_1.set('.empty', {scale : 0, rotationX: 360, rotationY: 360, rotationZ: 360}, '>');
tl_1.set('.empty', {backgroundImage: P.image.value}, '>');
tl_1.to ('.empty', {scale : 1, rotationX: 0, rotationY: 0, rotationZ: 0, duration: 10 * P.animation_duration.value}, `>${P.animation_delay.value}`);
tl_1.set('.tile' , {border: 0}, `>${P.animation_delay.value}`);
To slowdown the spinning-in relative to the tile-sliding change line 391, e.g. to slow it by a factor of 2 change the line to
tl_1.to ('.tile', {scale : 1, rotationX: 0, rotationY: 0, rotationZ: 0, duration: 2 * 10 * P.animation_duration.value}, `>${P.animation_delay.value}`);
Regarding the slow-fade of the grid-lines as done by @MusicalBox , it is not really possible for me to do as they are borders of width 1px. I cannot really operated on these independently other that to make them disappear, or change colour.
The HTML files for downloading in the posts above have been updated.