For being a poker player myself, and for having bought and spent my afternoons on the very first "Governor of Poker" game a few years ago, I can only recommend this amazing sequel!
My opinion may be slightly biased by the nostalgia; but I guarantee Governor of Poker 2 is one of the best singleplayer Poker-based game I've played.
Set in the good ol' far-west, with comic-like graphic style, great animations and sounds (If you play in a saloon, you'll frequently hear broken bottles, piano rag-time, and cheerings in the background!) and hilarous voice acting with strong stereotypical western american accents!
The game has nice strategy elements with economy management : buy houses, towns, carefully uses bank loans and generate earnings from your proprieties; just so you might save money for future tournaments... or pay off your debts.
And about the poker itself, I see no flaw in its gameplay. The bluff may work or not, depending on your style, but also depending on your opponent : each player will have more or less the same personnality throughout the game, and it's up to you to read between the lines and guess if he's a shark or a fish if you want to have a chance and beat him/her!
Finally, I will greatly recommend the Premium Edition, which brings much more content compared to the standard one; it would be a crime to miss that opportunity. And for all the achivement-lovers, there's almost 100 medals to win, from a simple "3st place in a tournament" award, to the trickier "Beat a flush with a stronger hand". Will you collect them all?
A wonderful casual game, which also include fully-customised quick games, in case you want to play a short game during your lunch time.