If you just pick the wider of the dimensions then you get a more even spread vs random direction.

main.cpp

@@ -24,9 +24,9 @@ int main() {
   using namespace ftxui;
   std::string reset_position;
 
-  auto c = Canvas(60 * 2, 50 * 4);
+  auto c = Canvas(60 * 2, 27 * 4);
 
-  Map game_map(60, 50);
+  Map game_map(60, 27);
   game_map.generate();
   Matrix &input_map = game_map.input_map();
   Matrix &walls = game_map.walls();

map.cpp

@@ -226,6 +226,6 @@ void Map::generate() {
     .height = height()
   };
 
-  partition_map(gen, root, 5);
+  partition_map(gen, root, 7);
   draw_map(this, root); // left
 }