In Gunfighter, a shootout game for the Magnavox Odyssey², two gunfighters face one another across a field filled with trees. In the United States the game was released as Showdown in 2100 A.D.
The object of the game is to shoot the other player's gunfighter. The first player to hit the other gunfighter ten times wins. The trees add some challenge to the game by deflecting bullets fired at them, sometimes even back at the gunfighter who originally fired. At close range it is possible to shoot through the trees. Each gunfighter has six bullets, and more ammunition is hidden in the tree which matches the color of the player's outfit. Each gunfighter can reload at any time by touching the tree where his bullets are hidden.
Source: Wikipedia, "Gunfighter (Videopac game)", available under the CC-BY-SA License.