This game was very fun and pretty well polished. The boomerang idea was a good use of the theme. I personally didn't run into an issue (besides not knowing I could hit myself with the red boomerang). I didn't feel like I got lost anywhere in any of the levels and I felt like the difficulty was tamed.
I do agree with a few other comments on the matter of music. I got really repetitive and after a while too much. I can't really knock you on it as this is a jam, but still yet it felt a little much and took from the experience. This was a good jam submission and so much can be done with this idea! Hope you take it all the way after the jam is over!