When you’re starting on a new design, it’s easy to think of a hundred cool mechanics and fiddly bits you want to include. But focusing on those obscures the game you currently have and makes it more difficult to develop what's called the "core loop" of your game.
The core loop of your game is the primary game system that the players interact with. It’s everything that’s necessary for your game to function.
Giving your players variable powers that change how the actions work for each person may be an awesome idea, but it’s not critical to your game functioning. On the other hand, a mechanic that everyone uses every turn (like card drafting or worker placement) is probably vital -- the game won’t function without it.
Stay focused on the core loop of your game, and cut everything else until the core loop is solid. Losing the fluff prioritizes the most critical part of your design, and ensures you have a solid foundation before you start adding sprinkles on top.
All those extra bits will come with time (if they’ll truly make the game better) but if you don’t have a solid core of fun, all the extra bits in the world won’t fix your game.
— Sara Perry & Peter C. Hayward