R-Type Delta is a horizontally scrolling shooter video game. Released only on the PlayStation, this is the fourth game in the R-Type series (hence Delta, the fourth letter of the Greek alphabet), and also the first game offering different fighters, with different Force and Wave Cannon combinations for the player to choose from. Set in 2164, Delta is also the first game in the R-Type series rendered in full 3D graphics. Source: Wikipedia, "R-Type Delta," available under the CC-BY-SA License.