That’s a really great question, kamilo – I’m doing some research on the way video games affect us at the moment, so hopefully I know a bit about this!
Some recent studies have looked at how brain training games help us, and what researchers think happens is that if you play them regularly, it makes you better at those particular games. However, they’ve not found much evidence that that benefit transfers over to other, similar things – so for example, if you get really good at the maths bits of the games, then that doesn’t actually mean that you will get faster or better at maths at school.
However, we’re still not sure whether this is the case for everybody, though. Research has also been done on things like action video games, and has shown that people who play them regularly tend to have faster reaction times and slightly better vision than people who don’t.