It's all in the angles snow drop!
On this level you can only shoot the bubbles to the right so to reach the bubbles on the left you need to bounce them off the walls. The tricky part is you only have a limited time to angle the shooter, and if you miss one it's really hard to complete the level. Just got to keep practicing those angle shots.
I have managed this a couple of times, but then I do spend a lot of time 'testing' these out when I add them to the Games Zone *
BTW, if you think this levels hard, wait until you reach level 6, I haven't made it past that one yet!