I think this game would have been more fun if the '1-1' was original and not almost directly copied and pasted from Super Mario Bros. 1-1 in Super Mario Bros. works because it is designed around Mario's movements whilst the characters here do not have the same movement as Mario and it just makes traversing the levels harder in a non-fun way. Like you can have an homage to 1-1 from Super Mario Bros. without it being directly copied. Some effects like the fire one was more annoying than fun and the darkness effect does not work at all for this kind of game as the jumps feel blind which isn't a great feeling whilst platforming in a game which sends you back to the start.
I liked the art which is pretty good and cute as well. I don't think this is a bad idea at all either, just needed some work!