To unlock them, you have to kill a Protoss called "Robin" on the map Critter Planet.
-The Protoss are realy weak in early game, but one of the strongest races in lategame. so a late Fleet-beacon rush is the tactic to use.
-In earlygame you have to make sure you have a hidden base, because the game is over when one of your unit types (elder protoss or worker) is killed completely.
-Protoss can use nearly every Food, but you have to make sure that you have enough near your base, so mushrooms aren´t as good as plants or fish.
-You will have about 30 units when endgame beginns, so make sure you have finished with upgrading.
-Use Bonfires to heal units after and/or while battle.
-Make sure you enemy can´t use his mass units as an adventage by using slim corridors and your rift ability, so the enemy can´t surround you.
-Use the Elder-Protoss skills to win every battle!
HP: 26 Energy: 0 Armor: 1,6 Attackdamage: 3,5 Attackspeed: 1,3
-Tribal Protoss elder
HP: 35 Energy: 60 Armor: 0 Attackdamage/Attackspeed: no attacks availiable
-You have 6 upgrade points you can unlock with 10mineral eack to spend for uprading the damage or health of your units.