Doki Doki SMB1 Club - Natsuki is another ROM hack of the original Super Mario Bros. (SMB1) for the NES. Like the Monika version, this fan-made modification integrates elements from Doki Doki Literature Club! but features Natsuki. It retains the core platforming gameplay of SMB1 but likely includes altered assets and/or gameplay changes to reflect Natsuki's presence.  Created by a fan, it is not an official Nintendo product.

Doki Doki SMB1 Club - Natsuki

Disk Hacker II - Copy Plus 3 (Japan) (Unl)