Final thoughts:
One, the code for longjumping is REALLY wonky. I can't get it half the time. If I hold crouch for too short, it doesn't register. For too long, it turns into a backflip. And you *repeatedly* require it! In Toad's Mining Company, like half the stage is locked behind two precise longjumps!
Also I think you don't understand the idea behind Star Gates. The point of gating progress behind stars isn't to make player beat every star. The point is the opposite, to allow player to pick and choose which stars they want to do and which they don't? Like, in Super Mario 64 you need 70 stars to beat the game - out of 120.Only 58% - not even a full sixty - is required to beat the game.
In current version, sure, you can unlock second stages after getting only 3 stars which is fine... but to unlock third tier of stages you need 12 stars. That's 100%ing two full stages! If you need help with thinking of how to structure the star gating, I recommend making a chart of how Super Mario 64 does it - count how much stars are available at each point, and how much is *necessary* to unlock next tier of levels, as a percentage. You will be surprised how freeform Mario games are.