I think the thing most lacking is that there is no penalty for missing in this. Other than that, and the things mentioned by other people, it wasn't too bad: a good little distraction if you've got a few seconds to spare.
It didn't really feel especially realistic to me - that is, it didn't feel like a balloon but rather like a generic movement device. I'd recommend greatly reducing the friction-type effect, so that when you start going in a direction, you keep moving that way.
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