game over if y >= nb_lines

source/GridMap.gd

@@ -42,7 +42,10 @@ func possible_positions(initial_positions, movement):
 		
 func lock(piece):
 	for position in piece.positions():
+		if position.y >= NB_LINES:
+			return false
 		set_cell_item(position.x, position.y, 0, MINO)
+	return true
 
 func clear_lines():
 	var line_cleared

source/Main.gd

@@ -169,9 +169,11 @@ func _on_LockDelay_timeout():
 		lock()
 		
 func lock():
-	$GridMap.lock(current_piece)
-	emit_signal("piece_locked", $GridMap.clear_lines(), current_piece.t_spin)
-	new_piece()
+	if $GridMap.lock(current_piece):
+		emit_signal("piece_locked", $GridMap.clear_lines(), current_piece.t_spin)
+		new_piece()
+	else:
+		game_over()
 
 func hold():
 	if not current_piece_held:
@@ -220,8 +222,9 @@ func pause(hide=true):
 	$Stats/Clock.stop()
 
 func game_over():
-	$FlashText.print("GAME\nOVER")
 	pause(false)
+	current_piece.emit_trail(false)
+	$FlashText.print("GAME\nOVER")
 	$ReplayButton.visible = true
 
 func _on_ReplayButton_pressed():

source/Main.tscn

@@ -229,7 +229,7 @@ extra_spacing_bottom = 5
 font_data = ExtResource( 11 )
 _sections_unfolded = [ "Extra Spacing", "Font", "Settings" ]
 
-[node name="Main" type="WorldEnvironment"]
+[node name="Main" type="WorldEnvironment" index="0"]
 
 environment = SubResource( 2 )
 script = ExtResource( 1 )