Create new bitmapdata (full screen size). Draw the shadows in it. Set the whole bitmapdata to multiply (and change opacity, if needed).
Underneath PLAYER SHIPS, display a shadow with the color (or glow/outline) of that ship. This makes them stand apart from the crowd.
Also, above PLAYER SHIPS (once revealed), display a bubble containing the avatars of the players inside the ship.
This immediately allows us to create the NIGHT MODE. Create dark overlay, cut out light sources (with radial gradient), set to multiply.
Multiple Units: If multiple units are on the same tile, they need to be spread out so they are all visible. They are allowed to overlap, as it is more realistic and looks better (and allows them to be a little bigger).
First, loop to check how many units are on each tile. Save that number.
When placing the shadow + sprite...
If multiple units are on the same square, spread them out to be able to show all of them.
Use a diagonal circle, with random deviations
Don't forget to set the z-index as well (don't change order in array, change drawing order), so that ships at the back are behind other ships
Shadows: Create shadow underneath each unit
Multiple Units: If multiple units are on the same tile, they need to be spread out so they are all visible. They are allowed to overlap, as it is more realistic and looks better (and allows them to be a little bigger).