You might be thinking of a stage in the game
Crossbow. This game uses a gun (crossbow) to move a set of cross hairs around the screen shooting on various dangers of the travelers you are guarding. You keep playing as long as you can get at least on of the travelers across the screen safely. You also gain additional travelers along the way as well.
From KLOV:
The stages are a desert, a ghost town, ice caves, a volcano, a bridge, a jungle and last but not least a castle... On some stages, a path may be blocked; like at the volcano, it will be blocked by a lava flow, so you will have to shoot the rock in order for your friends to cross over. Also, in the ice caves, you must shoot two big ice pikes into the two big crevasses in the path, so your friends can cross. When you get to the castle, you must shoot the chains to lower the drawbridge, so your friends can get inside.