Theme can inspire game design, but you have to be sure it doesn’t tie your hands. During development, you might discover that you need to alter a mechanism to make the game better. It’s hard to make that change if it goes against the theme.
Quotes about theme
If you’re playing a game with a theme, you have to feel it in the gameplay. You should be presented with the same problems and situations as those who experienced that theme first-hand. In addition, you’ll very often come up with mechanics that you otherwise would never have thought of.