Group similar planets together and collect the crystals.

Use your mouse to draw an area around a group of similar planets.
Depending on the amount of gems, you are awarded number of gems which can be collected by touching them with you cursor.
If a planet touches the line before it closes, the planet explodes and the line disappears, costing you valuable gems.

You will need to collect enough crystals to reach the level quota.
If you match 4 planets, you are awarded a multiplier. If you enclose this multiplier in a match you get a bonus.
If you match different planet, a black hole is created which need to be destroyed by drawing a circle around it.