Wrath of the Black Manta takes all the elements of the popular 'Ninja' games of its time, and manages to do all of them wrong. It's difficult not to compare this to the NES Ninja Gaiden ...

Press B, B, Select, A, Up, Select, Right and Start before the title screen appears. If done right, the word MUTEKI will appear. A, B, A, A, A, Up, Down, B Stage 2 ...