Wow, is that the first time we've seen a real post-credits thing since... well I was going to say that Painkiller one he did, but I guess you could count that thing he did at the end of the LittleBigPlanet review.
Anyway, yes, the game: Pity this apparently isn't all that good; this is probably the only real exposure it'll ever get. That's the thing about Yahtzee: His overly-critical approach works well to balance out the hype and overly-generous reviews that big-name games always get, but in cases like this, it's the only thing for potential customers to go on besides generic marketing text on the Steam store.
Making it about pirates was definitely a good move. If there's any genre that should have instant appeal for the sort of people who play video games but hasn't already been done to death by video games, it's probably pirates.
