I'm building a 2048 game in a single file with smooth animations, using a 4x4 grid of tile objects that track their id, value, row, and column. Each tile will render as a DOM element positioned with CSS transforms, and I'll add animations for new tiles popping in and merged tiles pulsing.

The traversal order processes tiles from the far edge inward, so merged tiles are handled correctly before source tiles get processed. The ghost tile approach works well since the merged tile is removed from the grid and animated separately. The win condition is being tracked with a truthy flag.

The issue is that checking `won` as truthy causes the overlay to re-show on every move after the first win. I need a separate flag to track whether the win overlay has already been displayed, so it only shows once.

The restore function correctly preserves the won state from the snapshot while keeping winShown unchanged, and the dead check still runs properly after winning. The merge logic traverses from the far edge with reversed row/column iteration to move tiles correctly, and since we process tiles from the edge outward, when we double a tile's value it won't be revisited later in the loop.