Well, the summary tells it all, this is just a short one-shot about Kaiji trying to pay his debts off without going to the ship. Since it is a one-shot, there is definitely not much at all to say about this, especially without spoiling anything.
If you were expecting any mindgames you usually would have expected from Kaiji, then no, there's nothing like that. Overall, i don't really even see the point of this one-shot. It's not terrible, but it doesn't really offer anything new or mindblowing.
If you're a Kaiji fan, then you might as well read it since it's so short, but otherwise stay away
and read the actual series. This isn't even good for giving a small taste of what the real series is like.