Cool idea using Toad's double-jump as the focus of the level. The decorations and graphics were good for the most part, and good music choices.
There are some areas that I think need improvement.
Firstly, the Windmill Animations. As of right now they look choppy (using only two frames it looks like). Not a big issue, but it would be really nice if you could get a smoother animation for them.
Speaking of the Windmills,
You might want to consider having the enemies in front of the blades. This koopa hit me when I first go to this area since it was pretty well hidden behind one of the blades. If the rotating blades are a NPC, you can use
in the NPC file
Next is this spiny. This set up is used 3 times in the level, but it's this particular one that bugs me a bit. In the other two sections the player has time to wait for the spiny to get into the position they want it to be. Granted you can do that in this section by constantly hopping on and off the falling platform, but some players (like my impatient self), will rush off this platform the first time they get to this spot and receive a nice face full of spiny. I wouldn't say get rid of it just yet, but just letting you know it's location is "iffy" to me.
Using the Beat-Block idea from Mario Galaxy 2 for the hidden star was a nice idea too. Although, I think you should fix two things here.
1. The sound effect. The
stab sound effect just sounds annoying IMO. Possibly use another one, like the
shield sfx.
2. Having played Mario Galaxy 2, I was expecting the beeps to line up with the song. It would be cool if you got the beeps to line up with the song.
Anyway, neat level you got here I liked it a lot. It was challenging and fun. Hope my feedback helps.