I have not found anyway to quit the game. It just keeps opening a new world with not choice to end the game. At this point I have to turn off my computer manually to leave the game. That is not good.

Which specific game?

For certain software programs back in the '80s, users were expected to either power down the PC, hard reset, or press Ctrl-Alt-Delete to reboot in order to exit the program running. This game, like a few other DOS games in the '80s, therefore doesn't have a quit option.

As this GOG release of Populous runs in DOSBox, you can use Ctrl-F9 to shutdown DOSBox and return to Windows.