Although planned for release for Japan this game was only released in North America. Nintendo had a strict violence policy but missed out on the blood drenched skeletons on the round start screens!
This is one of the few examples of a licensed NES game that somehow managed to slip under Nintendo's tight censorship protocol. Although the title screen for the US release was slightly altered (with green slime instead of blood), the game still featured plenty of gore, as evident in the second-half of the first level. The end is also particularly gruesome (not to mention bizarre).