It's Ninja Rahoi
That's one of the characters in the game and the pun "Ninjara", but I can't transfer it to English.
But frankly speaking - I've been considering to call it "Ninja's Tale" to avoid any misreadings. So it's either "Ninja Rahoi" or "Ninja's Tale" for the title screen...
PS: However, giving it a second thought.. It could be "Hey, Ninjas!" or "Hoi, Ninjas!"
"ホイ" is generally translated as "Hey" or an exclamation like that...
So. now I'm unsure about the title - great...