BLOCK AND KEY
The grid puzzles that you must complete in order to activate a memento are simple at first, asking that you match three of a kind on a 4x4 grid. Yet things grow steadily more complex. Red blockers appear that prevent you from moving a certain row or column; junctions change a tile’s expected route; other hazards can cause blocks to disappear entirely from view. They’re a little obtuse by game’s end, but won’t halt your progress for long, the small board size meaning that, if a solution can’t be found, it can at least be fudged.