Light animations - 2-dimensional
You can build an LED matrix using single LEDs but in most cases
the commercial one which come in 5 by 7, 5 by 8 or even 8 by 8
will do the job.
As they are stackable you can fix as many as you need next to each other.
You also can get the
offering 9 by 14 LEDs.
To power all the LEDs independently you need to install a multiplex control routine.
If you need more port than you got you have to think about decoder chips
or do the
as done with the LOL shield.