R-Type is set in the 22nd century, and the player flies a futuristic fighter craft called the R-9a "Arrowhead", named for its shape, and because it is the ninth model in the 'R' series of fighter craft (but it is the first of the series to actually be used in combat; the previous models were all prototypes). The mission is to 'blast off and strike the evil Bydo Empire'. The R- in the series title originally stood for "ray", as in a ray of light. It was a reference to the many different types of ray-like weapons in the first R-Type. his was later retconned in R-Type Final to refer specifically to the production code as well as a term of endearment for the player fighter craft, the "Round Canopy".

The original R-Type was well received by most gaming critics. However, it was also infamous for its relentless difficulty. It earned 7th place in IGN's Top 10 most difficult games to beat. The gameplay of R-Type is noticeably distinct among shoot 'em ups. Invariably the player will lose, not because of an inequality in firepower, but because of the design of the levels themselves. There is usually a 'correct' way to get through a level, but players must learn these by experience - i.e. by losing and restarting from earlier in the level. The game innovated with its weapon system compared to contemporary shooters, featuring a chargeable shot (beam-meter), and detachable 'force' pod; levels were designed to require different tactics and ideal weapons (air-air, diagonal, or air-ground laser).