After finding the reason for CircuitPython crashes in #µGame and getting the audio amplifier to work, version 4.1 has pretty much all the parts that I wanted to have. However, its physical layout is somewhat problematic, especially the rather large speaker smack in the middle of the board, which makes it hard to add a battery there.

So I started working on version 4.2. So far I have the following changes:

• Added guide holes for the USB socket.
• Larger footprint for the flash chip, so that more chips can be used.
• Smaller and cheaper reset switch.
• Pads instead of holes for the battery connector.
• Moved the audio amplifier circuit.
• Moved the speaker to the front of the board, and used a footprint for really small SMD speakers.
• Moved some components away from each other, so it's not as cramped.

I'm still considering two more changes:

• Add a voltage divider to an analog pin, for measuring battery voltage.
• Move the charging circuit before the switch, so that charging is possible with the switch off.

I think that 4.2 will be the last prototype, at least if everything works as expected.