vv221: Most of the time locale issues happen when using Mesa graphics drivers.
immi101: you happened to know why the mesa driver causes issues with this ?
This is most probably linked to the use of a ',' (comma) as a decimal separator in some languages, where the engine expects a '.' (period).
But I can’t really say more about this, I did not track the issues further, and I suspect there might be multiple ones.
vv221: Here are a couple games that have issues with the Mesa + non-English locale combination:
Faster Than Light (FTL)
immi101: wasn't that supposed to be fixed with the latest patch ?
After a quick check, animations are still not playing in version 1.6.7 when using Mesa drivers and French locale.