The European release of the figures features a quadlingual translation of the English card text, per regulations for selling toys in the European Union:
(The card on the right is a vintage release rather than the US recreation).
The "WHO YOU GONNA CALL?" variant, appears to be a second US release variant. Beyond that and the quadlingual translations on the backing card, there is no physical difference in the actual toys between their EU and US releases.
There are physical differences between the original 1980s releases of the figures, and the 2020 Kenner Classic run.
There are minor tooling differences all over the figures as they appear to be brand-new sculpts (with the biggest difference being in how the Proton Pack clips onto the figures' back).