Stacking pandas? I wasn't sure why I was doing that - but liked the bubble pop and positioning.
I think adding a wee bit more 'juice' to the landing or the pop (e.g. screen shakes or different landing effects) would be good. The music didn't quite fit more me - with the pandas... something a wee bit more oriental fitting would change the vibe quite a bit.
Good stuff getting the game jam submission completed and in on time!