No, for games that are freely distributed over the internet that law does not count since one cannot restrict the internet.
It's only when you sell your games here in germany you need to submit it to the USK (which is control unit of the government that puts different medias into the different age categories or bans them if appropriate) and the USK then gives it a certain age restriction (free for all ages, 6 yeas and plus, 12 years and plus, 16 years and plus and finally 18 and plus). Selling a game that has not been rated within germany is then also forbidden.