In Japan, R-Type was released on two Hu-Cards, each card with a different half of the game. The second half was confusingly called "R-Type 2" despite not actually being R-Type 2. In the US, both halves were put on one Hu-Card as "R-Type". Then, in Japan, the full game was put on CD with a remixed CD soundtrack as "R-Type Complete".
Did that help? Haha.