Mario in his Mario Maker costume in a SMW style. Great for Super Mario Maker styled Hacks!
This skin has a lot of smaller problems that add up.
First of all, you don't really need to replace the Nintendo Presents logo. It may be up to the player to use or not, but nobody is downloading player skins to get a new logo.
Many of the frames don't look quite right because the hat almost looks like it's cutting into Mario's head instead of something that he's wearing. Some jumping and falling frames also mess with Mario's eyes, and he looks like a bit of an odd duck.
His Fire Flower colors are barely different to his normal colors. There are also some changes to Super Mario's shading that could use some work - notably, his ears. The issue with his hat applies here, too.
A lot of Mario's flying animations are broken-looking.
Some more odd-looking frames here, but it also shows that Mario's hammer is missing in a few common frames, like when wall running and from a running jump.
Lastly, Super Mario's Yoshi-riding frames have some inconsistencies. The hat changes completely and the hammer goes away while turning around. There's also some broken frames around Mario's leg while turning.
All in all, I do think this is a worthwhile idea to work on, but it can use a fair amount of extra polish too. I would recommend getting some extra critique on it over by the Showoff thread or on #graphics in the Discord channel.