Pokemon Red/Blue/Yellow VC releases get PEGI 12 rating.
The release of Pokemon Red, Blue and Yellow onto the 3DS Virtual Console has gotten old school players excited to re-live those memories where there were only 151 Pokemon to catch as opposed to the 700+ today.
One thing we noticed on the special edition 2DS console being released with the game pre-installed is the PEGI rating on the box which has a 12 rating, which may surprise some people as most Pokemon games are either PEGI 3 or PEGI 7.
One theory is that the Game Corner which allows you to gamble your money for prizes such as items and even Pokemon is the reason for the increased rating. You won’t find Game Corner in the newer Pokemon titles due to stricter rating systems mainly in Europe.
Source: http://www.pokemon.com/uk/pokemon-news/classic-pokemon-games-return-on-virtual-console/