While it may not be quite as popular as it was a few years ago, the chances are Pokemon is a series that still needs little introduction. If you have a child around a certain age, it's likely they'll have seen a few episodes on TV shows, or at least be familiar with well-known characters like Pikachu. Much like the other games in the series' fifteen year history, Pokemon Black/White Version 2 lets you build up your own team of virtual creatures (known as Pokemon) who help you out in battles with other Pokemon, and grow stronger with each fight. Putting a team together, and building them up, it's up to you to catch new Pokemon, and train your team up, until you're strong enough to defeat the best Pokemon trainer in the region, the Pokemon Champion. With a huge world to explore, cool creatures to collect, and a simplistic battle system, the odds are Pokemon Black or White Version 2 will be a game they won't want to put down.
A large part of the game revolves around pitting Pokemon against each other in a Pokemon battle, but luckily, things are pretty easy to pick up. Each Pokemon is capable of learning only four moves, so it's up to you as a Trainer to decide which ones are most useful, before putting them to the test in the take-it-in-turns battling system – whether you're against a Pokemon from the wilderness or a fellow trainer. The battles can be as strategic as you want to make them too, whether you prefer to just smash your opponents with an assortment of damage-dealing moves, or would prefer a more strategic approach, lowering their defence, confusing them so they attack themselves instead, or even putting them to sleep, leaving them open to attack. Each Pokemon belongs to one (or sometimes more) of seventeen different elemental types, each with their own rock-paper-scissors style strengths and weaknesses. An awareness of these types, that fire beats grass, water beats fire and electric beats flying, are a definite advantage as the moves deal double damage, although it's by no means essential to memorise them all either.
Perhaps the only real stumbling block for children is likely to be the fact that the game is very text-heavy, so a decent reading ability is a must. That said, Pokemon is the sort of game that they'll enjoy so much and actively want to play, that it may well have the added side-effect of helping your child improve their reading without them even realising it.
With it's emphasis on caring for your cohort of creatures, friendship, loyalty and growing up, there's nothing untoward in a Pokemon game. Yes there are battles between Pokemon, but they're never violent (you never see your Pokemon land a blow on an opponent, and any attacks don't leave marks), and your Poke-companions never die – they simply faint and can't battle again until they're healed at a Pokemon Centre, where they'll be revived, good as new with no ill effects whatsoever.