In the Metroid games, the Ice Beam is the primary weapon against the Metroids. Samus would need to freeze them in order to get a hit with a concussive blast from her Missiles. The Ice Beam is also used to create platforms from various enemies in order to proceed or reach those hard to reach power-ups.
The Ice Beam can be used to perform a special attack in Super Metroid:
1. Equip the Charge Beam and ONE other beam ability e.g. ice or wide (NOT two)
2. Select the power bombs but do not enter morph ball mode.
3. Charge your beam up and you should use one of the following secret attacks:
Ice- A shield will form around you damaging enemies you touch
Wave-Energy Balls circle you then Fire away from you in various directions
Plasma-Same as wave but with Plasma effect
Spazer- Large beams fire away from you like shrapnel
4. This will use up one of your Power Bombs (It may not work if you've just finished charging, give it another second)