Whether it's best to start designing a game with either theme or mechanics is hotly discussed topic (spoiler: different games/designers do it differently). But whichever way you start, I believe it's best to iterate using both approaches, blending crunchy mechanics and silky theme, like a perfect baguette.
The Theme-Mechanics Seesaw
The Theme-Mechanics Seesaw
The Theme-Mechanics Seesaw
Whether it's best to start designing a game with either theme or mechanics is hotly discussed topic (spoiler: different games/designers do it differently). But whichever way you start, I believe it's best to iterate using both approaches, blending crunchy mechanics and silky theme, like a perfect baguette.