The LED matrices I'm using in all the other PewPew are great for several reasons: they have large pixels and small resolution, perfect for the kind of games I want to teach, where you don't have to worry about graphics. They are made of plastic, so are robust, scratch-resistant and light. And they only have 16 pins for soldering, and can be easily soldered by hand. But can there be anything cheaper?
How about individual LEDs, like on the MicroBit? They are cheap, right? Well, the components themselves are cheap, but the soldering of 128 pads is not. And forget about doing it by hand. Plus, they don't look very good.
Hmm, what else has a lot of LEDs in it, but only a few connectors, and can be had for cheap?
How about those tiny little OLED displays? They only require a few pins to control, they are cheap, low-power, and they have more LEDs on them than we need. Sure, they are also usually monochrome, but because they have much higher resolution than we need, we can use dithering to get our required 44 shades:
We even have some room left on the sides for some indicators!
Plus, if we added support for them to displayio, we could even have proper error messages displayed on them when something happens. That's an improvement in functionality.
(As an added bonus, it will probably be able to run arduboy games...)