I have visited Iga Ninja house (replica) and museum in Mie prefecture, Japan. In house, there are a lot of interesting tricks: Turn wall, secret door, peephole etc.. Also I got various Ninja's activity in the museum. I implemented several tricks, derived from Ninja, into Mysterious Mansion as below:
Push a wall to turn it and go through the next room..
When Ninja intends to get over a wall, he stick his blade to ground and step on it, jump the wall. Therefore, Ninja blade was shorter than Samurai's one.
I also want to implement a lot of remaining tricks in future game.