I have to agree with Computer-ronin.
The game is soothing and easy to play. I didn't feel any sense of rush other than the timer (and even then that was only because i decided to pay attention to it.
The design of the nucleus is what makes it personal because, as Computer-ronin stated, it depends on how you collect the particles. The only level this doesn't apply to is Level 14, where the only solution is to collect one at a time.
I gave it a 9/10 because i was hoping for more levels. This game is addicting, man.