Assault Suit Leynos, released as Target Earth in the USA, is the first game in the Assault Suits series. It consists of 8 stages. Much of the game's mechanics fall in line with those of horizontal shooters with some subdued platforming elements. The player's performance after completing a stage dictates what weapons, armor, and accessories are unlocked in the next stage. The game features 14 weapons, which was considered a lot of firepower for an action game in the early 90's. The wide assortment of armaments increased replay value by encouraging the player to experiment with different ways to defeat enemies.
