I like the concept, but it doesn't really feel like you are a boomerang as the monkey never picks you up or has to throw you again.
Maybe adding a certain time you can spend away from the monkey could add more depth to the gameplay and make you feel more like an actual boomerang. For added strategy, maybe if you don't make it back in time the monkey would have to pick you up, risking damage? The longer you stay away the more damage you'll do, incentivizing risky gameplay? Just a few ideas, there's plenty of ways you could go with this.