A Simple LED array counters for board-games or for kids. 
Using 4 micro switches and a sliding cover, you can reset the counter just by pushing the cover.
It uses a RP2040-zero, which is a smaller size Raspberry Pi Pico, but a normal Pi Pico will work as well.
Te code for MicroPython, so you need to flash the controller for MicroPython and it only requires the Neopixel library.

Two versions: 2 digit counter using one 8x8 LED (_64 in the files) array or 3 digit counter using two 8x8 led arrays (_128 in the files).

Bill of material:

• 1 RP2040-Zero (Raspberry Pi Pico),
• one or two WS2812 smd LED 5050 RGB 8x8 64 LED Matrix,
• 2 or 4 2.4mmx6mm self tapping screw for fixing the switch LED arrays (hot glue should work too),
• 4 micro switches (push buttons),
• 1 lithium-ion polymer battery 3.7 V (1000mAh for the small one-digit version and 3200mAh for the two-digit one),
• 1 SPDT Slide Switch (for switching on/off the device),
• 2x 2.4mmx8mm self tapping screw for fixing the switch,
• 1 TP4056 USB-C Lithium Battery Charging Board,
• wires.

Wire diagram: link on Cirkit Designer IDE here.

3D models available on Onshape:

• One-digit model here,
• Two-digit model here.