It's not specified in the rules, so are hidden characters allowed in cheat-less%, or is it considered a cheat?

That's what I figured, just wanted to make sure. Thanks!

I was unaware that there were secret characters in the game at all! How do you enter the cheats to get the characters? I'm playing on the original Sega Saturn

http://www.ign.com/wikis/saturn-cheats/The_House_of_the_Dead_Cheats

Here ya go buddy.