The Tales of Sir Regal -NES-

 A NES-themed Metroidvania game by KuroGamedev

The Tales of Sir Regal is a fantastic metroidvania game for NES 

 

Princess Melon has been kidnapped by evil forces. Sir Regal has taken up the challenge to track her down as rescue her.

Navigate a medium-size castle sub-divided into six separate areas. Includes 16 different upgrades, a 24 x 24 map grid, 143 rooms, 4 bosses, and a couple dozen enemy entries.

Video:

 Play, here

Source:  https://kurogamedev.itch.io/the-tales-of-sir-regal