While searching on Google I came across a game called Dreamcast Poker. Unfortunately the game didn't get passed alpha and was only available on Windows. I opened the Poker.exe that is available on the site it looks like you couldn't even play a game it just shows a demo of what could have been I guess. Kind of odd considering it was going to be a Dreamcast release unless it was going to be some sort of Terminal game.
The developer states in a readme file from the dcpoker-0.0.1.tar file
"(Matt Pruitt) This is the first realease of Dreamcast poker. It doesn't actually run
on the dreamcast yet. It's basically just going through a check to rate
the players hand. It only checks player1's hand at this time, but it caneasily check all the other players hands."
I don't think you'll be hearing anything about this game considering the files were released in 2005 so I supposed the developer decided to drop this project.
Well if you want to check out the game you can get it at the link below however there is nothing playable.
Dreamcast Poker: https://sourceforge.net/projects/dcpoker/