Knightmare, known in Japan as Majou Densetsu (魔城伝説), is a 1986 MSX vertical scrolling shooter computer game. The player is a knight, Popolon, who has to fight his way through several levels to defeat Hudnos and rescue Aphrodite.
Knightmare was an innovative upward-scrolling shoot 'em up game on the MSX system. The top-view graphics were considered very sophisticated for its time, similar to other MSX games such as Nemesis and Penguin Adventure.
The graphics are also notable for being developed with a keen awareness of the Texas Instruments TMS9918 Video Display Controller that the MSX incorporated. The enemies (notably the bats) had additional shadow sprites that, being placed at a vertical offset, did not add further pressure on the max-4-sprites-per-scanline limit of the TMS9918.
Source: Wikipedia, "Knightmare (1986 video game)", available under the CC-BY-SA License.