I finished up the second PCB — added the switches, the battery charging, the speaker, and even added a LIR2032 battery on the back. I will be developing my sprite library now.

Of course the first (well, second, but first physical) prototype has a number of problems. I will write them down, so that I can fix them when I make the next version:

• Make it wider.
• Center the actual display part of the screen, leaving some margin on one side.
• Use smaller buttons and arrange them better.
• Use a smaller reset switch.
• Make proper pads for the battery holder, or consider a battery connector.
• The parts that have to go on the back should be in the center of the board, not where you put your fingers. The power and reset switches can go on top or bottom.
• Mounting holes under the display make no sense.
• The pads for the display need to be longer, for more convenient soldering.
• Don't cram everything so close to each other.
• Add analog pin and a voltage divider for monitoring the battery voltage. Maybe even consider battery protection circuit.