bugfixes and design changes

Tetris.cs

@@ -516,11 +516,14 @@ namespace Tetris {
 
         // Method to be called when the button for placing a block is pressed
         public static void placeDownBlock() {
-            // Move block to the lowest possible point
-            while (!collisionCheck(player.x, ++player.y, player.positions)) { }
-            player.y--;
-            // Place the block
-            placeBlock();
+            if (!gameOver) {
+                // Move block to the lowest possible point
+                while (!collisionCheck(player.x, ++player.y, player.positions)) { }
+
+                player.y--;
+                // Place the block
+                placeBlock();
+            }
         }
 
         // Method to end the Game