It's hard to call this unique when there are many "connect 2 or more" games like this on NG. The game is all right, but I'm not sure why certain coloured balls like the red will change to a darker tone in the further levels.
The spaces between the bubbles can make clicking tedious, but I'm sure that would be an easy fix. I played to level 5 and saw no real change in variety to make the game more fun. Sure, new bubbles appeared, but that didn't add to anything.
This game's been done hundreds of times before. Perhaps you could take a new spin on it.
well... good enogth... but nothing special