Solution
The flavor text hints at Two Bits. Every country present can be associated with a value in Two Bits based on its ISO 3166 alpha-2 code. Subtracting the codes on the right from the codes on their left, as suggested by the title, yields A1Z26.
| Country A: | Code: | Number: | Country B: | Code: | Number: | Letter: |
|---|---|---|---|---|---|---|
| Tanzania | TZ | 20 | Denmark | DK | 1 | S |
| United Kingdom | GB | 50 | Belize | BZ | 30 | T |
| Peru | PE | 45 | Algeria | DZ | 44 | A |
| The Congo | CG | 83 | Barbados | BB | 65 | R |
| Bhutan | BT | 28 | Czechia | CZ | 24 | D |
| Togo | TG | 17 | Kenya | KE | 12 | E |
| Georgia | GE | 42 | Portugal | PT | 19 | W |
STARDEW