A more generalised word like "casino" or "game" would be a pass (Casino in Slovakia / Games in Slovakia, which then may relate to slot games etc). Having just "slot" is tough, IMO
I am not worried about .sk as a ccTLD (sold six figures worth of .sk in the last five years).
However, this isn't domain that would sell well in the country, because it's english word. I just thought maybe the keyword is so good, that even in a minor ccTLD it would have value. For example, sold kio.sk for mid $x,xxx recently which is not a name someone would value in Slovakia, but it is a nice hack apparently.
Anyway, I think @jhm has made a fair point here - it would take better/more general word to make it valuable.