Really like the look of this and the rain collecting on the blocks is neat.
So my first thought was to do something more with the mechanics, you already have a nice look and sound. I would suggest doing something more with the water and instead of the game just ending when the blocks get to the bottom, have the water slowly build up as you play and instead of game over when the block hits the bottom, have them float in the water. This would work on a couple levels, it would give the ball a chance to bounce off the floating block and also free up move movement for the paddle, you could also set up stacks of floating blocks on the bottom to create cool combos and ricochets. You would need to think of a new game over condition though, which could be the ball lands in the water, or the floating blocks stack to high.
Also I think something could be done more with the pattern of the blocks, would be neat if they built little reservoirs to collect more water as they came down, or were in a more interesting pattern :)
A lot you can do with it :)