First things first:
When you first launch the game it may default to 800x600 full screen. You can change this from the main menu. Select the settings gear in the bottom right, choose VIDEO, then the last two options are for resolution and full screen / windowed.
When installing you may need to download .net framework from microsoft. It seems that is only needed when running on older Windows (7/8 etc.).
You can absolutely switch back to the Flash version of the game at any time. If you come back to the WGT site and notice there is no PLAY NOW button select the MY ACCOUNT dropdown, log out, and then log in again. This will return all the flash elements.
Some issues we're already aware of:
Club chat is a little wonky and the chat can overlay the text input box
Selecting a club from the leaderboard in the country club section gives a blank page
Floating Toptracer box is a bit of a pain and resets back to the middle of the screen even after you've moved manually.
"Winner" Splash Screen in coin games doesn't always show in coin games
Spacebar does not yet change cameras
Mouse scroll does not change selected club
I'll add more to this list as we go.
_CHAMPION