In this hack I made for Spring Break this week that the beach is horrible and dirty. And Mario or Luigi needs to save the day. Wendy O. made mess on the water from the beach because, she want to ruin the Spring Break Vacation or party as well. So anyways. Good luck with my hack. I also I inserted the Anti-yoshi block remove for castles so they don't glitch.
A very nice fun hack with cool level design and palettes. I liked the wall jump ability and goal point bonuses =]
I think however that you put way too many coins in all your levels, making collecting them too easy and so less interesting.
There is an orange pipe near the middle of the fortress that, when entered by the bottom, leads you to an infinite bonus stage which softlocks you and so forces you to reset the game.
I would also personally put the difficulty to "easy" rather than "normal" as the game is really easy, especially with so many lives you can get thanks to all these coins and yoshies. The bosses also are even easier than the original game ones.
This hack has some pretty average level design. There are some questionable design decisions. For example, there's a section where the water is solid in the first level despite looking exactly the same as the other water that isn't solid; there is layer 3 water in the cave level where the level can vertically scroll, but the water doesn't; In one sub-level of the final castle, you can literally go above the entire level; etc. Okay, there's a lot of poor design decisions here. I'm glad it's short. Not surprised that this is your first hack.
This hack is a pretty decent short hack. It has nice graphics and some nice music. The only concerns that I have is that sometime the level design is lacking a bit and could be made better. It would also be nice to have some credits at the end. It has some other minor problems like a cutoff tile or two but nothing major that prevents it from being accepter. The other advice that I wanna give you is that it would be better if your next hack could have more levels, this barely had enough for a 30/40 minutes playtime. (I also fixed the tags cause you had some invalid ones)