Enter the ambient world of Osmos: elegant, physics-based gameplay, dreamlike visuals, and a minimalist, electronic soundtrack. Your objective is to grow by absorbing other motes. Propel yourself by ejecting matter behind you. But be wise: ejecting matter also shrinks you. Relax… good things come to those who wait. Progress from serenely ambient levels into varied and challenging worlds. Confront attractors, repulsors and intelligent motes with similar abilities and goals as you.

VirtualRiot says

8/10 - Agree (2) Disagree

Lay back and chill.
Ambient music slows you down while you move your little bubble through blue world full of other bubbles with different abilities to stop you from growing.
You need to kill 30 minutes? Osmos is the game! Perfect for a break, but only for that, because it can bore you after a time.