Sewer Crystals
When you reach planet Aquatos, you will eventually be led to a sewer system, which is filled with large and small Amoebas and crystals in cages. In it are tons of sewer crystals to collect. The plumber from the first two R&C games will offer you lots of bolts if you collect the crystals for him. At the time you reach the level, you can go into the sewers and collect a lot of the crystals, but most will not be obtainable until after you get the Gravity Boots on a later planet, which will allow you to walk on the walls and ceiling of the sewers. It's best to wait until you get the boots until you go through the sewers, collecting the crystals.
Once you do get them, you can walk along the walls and ceiling of the sewer area you can see on the map to reach hidden sewer areas not on the map. In the hidden area is where you will find most of the crystals.
Throughout the entire sewer system, the area you can see from the start and the hidden area, will be crystals in cages. Hidden in the sewer water or right out in the open will be many Amoebas. You can kill them as you come across them, or just walk on the walls and/or ceiling and avoid them. You will probably kill most, but the sewer system is large, so you could run out of ammo or get attacked a lot and you will need to avoid as many Amoebas as possible because you will have low health.
Most crystals will be scattered on the floor of the sewer, but some need to be obtained another way. Sometimes, gigantic Amoebas will drop down from the ceiling and attack you. They take a few shots from your weapons to kill, but when you manage to take one down it drops a sewer crysal. There are many of these in the sewers, so keep your eyes open for them. Once you get the Map-O-Matic on a later planet, it will show you where every crystal and giant Amoeba are, which is very handy.
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