In Svelte,

  <Board {game} />

Is just a shorthand for:

  <Board game={game} />

Spreading also works, although it's not nearly as used:

  <Board {...{game}} />

Boolean HTML attributes like "checked" can be used with boolean variables as-is:

  <input type="checkbox" {checked}>
  <input type="checkbox" checked={someBoolean}>

I highly recommend anyone to go through the tutorial (at least once Google Cloud Run issues are solved) to get a feel of how things work together.