Cowboy Kidz has you riding alongside a moving mail train in a constantly upward-scrolling landscape, fending off danger as it appears. You protect the train by shooting or dodging bandits, switching between riding in front of or behind the train to reach the other side. Rocks and cacti must also be avoided, as touching enemies or obstacles costs one of your lives. Later stages increase the challenge with bandits firing from the train and rivers that can only be crossed via bridges, making positioning and quick reactions essential.