Osmos/Ambient

In the ambient levels, the player's mote typically floats in a large area surrounded by inactive motes, and must become the largest or simply very large. Variations on this theme involve, for instance, starting the game as a very small mote surrounded by lots of larger, fast moving motes, or the presence of "antimatter" motes which shrink normal motes during collision no matter which one was originally bigger, or starting the game stuck in a huge, densely packed area with a large number of other motes without much space to move about and having to nudge other motes out of the way by ejecting mass at them.

A3C - antimatter
Often you will start with very few motes that can be absorbed within ready reach. As in the earlier impasse levels you will have to push against other larger motes to get them to move away or into each other.

Antimatter motes can be used to decrease the size of big motes.

Larger motes can be pushed into an even bigger one. Once the smaller of the two motes start getting absorbed, wait close by and move in to absorb the shrunken mote once it gets smaller than you.