Some sort of RP2350 or RP2040 dice, where it could have sensors (like accelerometer and whatever sensor can tell which way is down) so that it knows what was rolled, and maybe screens on the sides. If not screens, maybe one side could snap off and the programming port and BOOTSEL button are there. Maybe RM2 chip (or other) for wireless projects (i.e. showing what was last rolled on your phone), but there’s probably not enough space in it for that. The battery is probably the biggest size issue.