Nova the Squirrel
You can also get the game from itch.io!
This game takes inspiration from Super Mario Bros. 3, Kirby Super Star, Chip's Challenge, and Hannah and the Pirate Caves. In many cases, Nova will have to copy abilities from enemies and then use them to solve puzzles.
Engine features include cutscenes with variable width text and portraits, and moving platforms.
There is a level editor that I think is a lot better than Tiled, named PrincessEdit.
This is an open source project and it also exists to develop the Princess Engine (named because its goal is similar to President ) into something that's useful for other programmers to use to make their own NES platformer game. This engine will provide something much more legal to play with than hacking a game in the Mario series. In addition, unlike with Super Mario World, all the tools as well as the game itself are completely open source, and GPL licensed.