Okay, its a bug unfortunately, You can read about it below in the comments, but it has nothing to do with the star. Often its not possible to get to the star.
Though technically You actually aren't stuck here - You just need to go beyond the left part of the screen , and navigate to the bottom. The level generator sometimes breaks in this regard unfortunately, but there is always a route, just sometimes leads backwards. Its silly I know. You can also just restart the game to see a level generated differently.
I also advise to play in full screen, then You can see a bit more and it gets easier.