When I create and start a game with no other players just to try some strategy, learn shortcuts,... it seems impossible to delete that game. When I leave the game it stays there forever. I only see buttons START, JOIN, REFRESH,...
Is it not possible to delete a game?
This behavior does indeed occur. The game IS gone, it just shows up. I'll look into why.
You should still be able to create a new game (Which will replace that one), and the issue is local only, and only shows up to the person that created it, I believe.