Interesting idea!

This was a great idea. It could be a lot better by slightly extending the display time of each bubble and refining the graphics.

Good

But too hard :/

I had difficulties even on the first level O_O

You should really make the circles expand for a longer period - a game like this with levels, should start nice and easy and enjoyable, not hard from the first moment and boring, sorry... but that's the truth. You'll probably improve with your next game ;)

And please have some background music too :)

wait...

Let's start: I know that there are tons of chain reaction games, I like them alot. This one is just as simple as that, but there are some things wrong and to express myself with the fewest words, i'd say: it's basically Boomshine, BUT without what made that game (almost) unique, was that a nice background music where the SFX fitted perfectly, nice visual effects, a less frantic try again... There's just nothing "good" about this game that could make me play it instead of that, but I don't want to be mean since i like the kind of game, so I won't bring you down. Just try to take original roads..

oh well,

idk, but I guess some circles just don't explode on collision, some circles have too less of a lifespan, graphics could be better and there should be more than one sound.

It's not great, but it's not a failure.

Keep it up!