Unfortunately, the ports suffered from slowdown, unresponsive controls and no credits. Some graphical changes were made that removed parallax scrolling from the backgrounds of the levels. Other graphical changes were made to comply with Nintendo's "Family Friendly" censorship policy at the time (i.e. a pool of blood changed from red to green, and the removal of pentagrams). Fans also complained about the omission of some music tracks (including removing two pieces of music from Ninja Gaiden III, and replacing any use of the first stage music in the Ninja Gaiden II cutscenes with a repeating footstep sound).