boolean can_pass_to_walkable; /* player can pass to empty or walkable tile */
boolean grow_into_diggable; /* amoeba can grow into anything diggable */
boolean auto_exit_sokoban; /* automatically finish solved Sokoban levels */
+ boolean solved_by_one_player; /* level is solved if one player enters exit */
boolean continuous_snapping; /* repeated snapping without releasing key */
boolean block_snap_field; /* snapping blocks field to show animation */