Sounds good! Your game reminds me most of Puzzle Bubble arcade games; they had a system where they showed you a preview of the first bounce or two, if I remember correctly. But I totally get your reason for doing the aim the way you did. If you keep developing it and add more obstacles the preview would eventually be moot anyway in terms of difficulty.
One other thing, is that if you eventually target mobile platforms I think it would be a really good fit! Then you wouldn't even have the issue with the mouse!