Would be great to be able to change the board size to like small, medium, or large

The game could lay out the move options at onset or after first click of each piece so that a user unfamiliar with chess can begin to learn.

It would be nice to have a clear board / start over button instead of having to refresh the page.

Something to look at is to use some functions/for loops to create arrays that can then be looped through. For example, setting the click filters starting on line 136

When moving the white king who's turn isn't switching so while moving white king, white player gets unlimited moves. Watch the video in the zip file linked below for example.

issue1.zip

One way to avoid switch statements is create a method where your properties are the values are objects that contain the information you want to do. For example, the switch statement that begins on line 49 could be refactored to look like

var pieceLayout = {0: {piecename: 'white-rook', piecetype: 'rook'}, 1: {} }
myTile.piecename = pieceLayout[i].piecename;
myTile.piecetype = pieceLayout[i].piecetype;

The board could be bigger and have some kind of background/images and/or animations.

It would be great if the chess game board / pieces were responsive to the size of the window.