This seems cool but I can't help but think it should be named Brandy since brandy is distilled wine and whisky is something different.
It's the purchase that is so often regulated.
(And you're right, in many places the latter limit is lower than 18. For example in Germany, Austria, Switzerland, Denmark and Belgium, non-spirits like wine and beer can be bought from 16.)
The two (drinking age vs. alcohol buying age) often get confused, but consumption limits per se are actually pretty rare. (Assuming it takes place in private – laws regarding drinking in public are somewhat more common.)
[1] https://scotchwhisky.com/whiskypedia/1888/royal-lochnagar/
Plus it goes with the whole gaming port thing