You can try reporting the video but that probably won't do much (doesn't mean it's not worth a try). The best you can do is treat it as free advertisement and hope it'll encourage people to buy the game if they like it.

Remember that pirated copy does not equal lost sale, especially for an indie title most people won't even hear about.

Edit: well, the double check by the other user makes this thing pretty sus. Either way, my comment still stands in case this really happens for someone.