My other idea is the EXACT same but their is MUCH more work involved to it.... Ill just post it....
Different Classes: Predators:
Brawlers: (Weapons) Strong Melee Attack
Hunter: (Weapons) Melee attack, mounted sholder blaster.
Stalker: (Weapons) Weak melee attack, sniper rifle.
Vanguard: (Weapons) Long skithe like weapon (Thing death has) Which gives strong melee attack.
Spear Master: (Weapons) Long spear.
(Here and down costs money)
Military Hydras: Strong Melee attack, fire rockets from their back,
Military Blazers: Strong melee attack, Shoot a beam much like the shrine
Aliens

all spit acid)
Drones: Spit hive noads on ground when aliens stand on them they are auto healed.
Slow, Weak Melee attack
Runner: Extremely fast, weak melee attack
Warrier: Normal speed, Normal melee attack
Queen: Normal Speed, Strong melee attack (only one)
(From here and down it costs Money to pick these classes and their can only be so many)
Predaliens: Strong Melee attack, Relativly fast.
Carrier: Normal Melee Attack, Has a bit more Hp then normal aliens, Normal Speed
Ravenger: Outstanding Armour, Outstanding Melee attack, Normal Speed
Yes i know that it is completely copying AVP Extinction the game... But hey zone copied star wars so why not.... (just an idea)