R-Type series

(Canon chronological order: R-Type > R-Type Delta > R-Type II / Super R-Type > R-Type III: The Third Lightning > R-Type Final > R-Type Final 2. R-Type Leo is set in a parallel universe.)
 * R-Type
 * R-Type II
 * Super R-Type
 * R-Type Leo
 * R-Type III: The Third Lightning
 * R-Type Delta
 * R-Type Final
 * R-Type Final 2

Spin-offs: The two R-Type title spin-offs are not SHMUP games, but turn-based tactics games set in a parallel universe. The following Irem titles are canonically related to the R-Type universe because these fighters are playable in R-Type Final and R-Type Final 2.
 * R-Type Tactics/R-Type Command
 * R-Type Tactics II: Operation Bitter Chocolate
 * Mr. HELI no Daibōken/Battle Chopper
 * Image Fight
 * X-Multiply
 * Armed Police Unit Gallop/Cosmic Cop
 * Image Fight 2