It's good. An original idea, but it's a little difficult to really get going (I agree with remco below, that you can make a mistake, and after that it's difficult to recover back to where you were), though I will say that when you do get the momentum going, it's quite fun to bounce, water, plant, bounce.
A quick side note, it's hard to see how the game could scale if it were made into a full release. Perhaps there could be puzzle aspects, if the controls weren't so difficult?
Great interpretation of "out of control" though (in terms of the out-of-control plant, not in terms of the difficulty with using the controls themselves; that seemed incidental and not an intentional aspect of the theme). And I love how the character changes colors when it has water - that was a smart idea!