I think this game is good, but needs a bit of work to make it slightly more fair on the player.
I felt a lot of frustration during some levels being unable to get past them unless I did EXACTLY what you designed the level for meaning no room for error or exploration with the controls.
I like a puzzle platformer with more freedom to the level design that gives the player the ability to do whatever they wish to complete the level.
That all said because this is a game jam version take all that criticism with a larger grain of salt because for the time you have you done an excellent job making this game. I just hope you take the feedback from everyone on board if you wish to continue development of this.