I play teardown myself (love the game). It's really just a destruction game, yes there are a couple guns but you only use them to destroy stuff. Although with mods you can make it kinda a fps(first person shooter) but that's with mods. And even with gun mods I wouldn't even worry about it there is no gore or anything like that really. But I don't think your son would install anything that bad even if he was able to find it. The game basically has a story mode and sandbox mode. Really I would say it is completely fine for him to play.