My kid (9 yo) has a One X, and has had for a few years, and we have a games library of around 200 games. Everything from AAA FPS, racing games, Fortnite, Minecraft etc. He plays and has access to it all.
The other day I downloaded Galaga to play for a bit of fun. He played it with me and absolutely loves it. Its now his favourite game. He jumps all over the place and can’t stop playing it.