In the original MS-DOS game, all sprites were 64x64 pixels. Instead of using formal transparency, the color #980088 is designated as transparent, giving all extracted sprites a purple background. Most non-boss enemies have a sprite for each of the nine directions they may be facing, for each of the Stand and Chase (and Path) states.
Later ports after the SNES used higher resolution, 128x128 sprites. However with the SNES, only one sprite for each state was created, so the enemies always appeared to face the player.
TriviaEditSome enemy sprites have pixels which are colored #600064, which is similar to #980088 but not the same. These pixels are not made transparent, and show up in game as purple.
- The purple pixels are normally meant for Mutant blood. Otherwise, it can be assumed that it is a mistake by the developers.