Simplify the following text for a Grade 6 native English-speaking person.
Original: Shigeru Miyamoto thought that the original Super Mario Bros. 2 was too hard for Americans , and decided to take the game called Yume KÅ jÅ : Doki Doki Panic , and replaced the old characters with the Mario characters Mario , Luigi , Princess Peach , and Toad .
Simplified: Both Yume KÅ jÅ : Doki Doki Panic and Super Mario Bros. 2 were directed by Kensuke Tanabe .