The final version of the techtree and units are as follows...
Tier 0
-Murloc Tiderunner
Tier 1
-Spider Crab Limbripper
-Sea Giant
-Hydra Hatchling
-Mur'gul Tidewarrior
Tier 2
-Elder Hydra
-Gargantuan Sea Turtle
-Makura Tidal Lord
-Mur'gul Shadowcaster
Tier 3
-Ancient Hydra
-Stormreaver Warlock
-Dragon Turtle
-Enraged Jungle Stalker
Temple of Boom
-Goblin Robo Spike Trap + A simple trap that can burrow underground to deploy an automated spike stabby power..
-Goblin Drill Tank + The name says it all. Designed for attacking buildings with it's Demolish and Pillage abilities.
-Goblin ATnT + A mechanicle walker unit with a decent chaingun. Uses a Scattergun in remenisence to the Flying Machine's Flak Cannon.
-Goblin Sapper + The old demolition standby. Kabooms! units and buildings to bits.
-Goblin Zeplin + The only FREE unit availible carries 10 units anywhere required
-Goblin Shredder + Though there is a lack of trees, Shredders can shred other things with those sawblades...
-Goblin Blaster + Is it a Shredder, or is it a Blaster? If it fires at you longrange, it's a Blaster.
-Goblin Incinterator + The Incinterator is the pinacle of Goblin TecKology, used for making fires out of structures and roasting units to a tasty crisp. Uses Incinerate, Demolish, and Liquid Fire.
-Select Unit + Selects a Hero Unit to sell Items
-Goblin Land Mines + Another staple of base defence. Land mines are deployed at chokepoints to blow up any unit that crosses it.
-Goblin Radar + A simple Radar unit with True Sight, comes in a 3 pack and is deployed like a Land Mine, with less boom. Also stealthy.
-Goblin Sentry Turret + A land Turret used to fire at enemies. Also uses the Scattergun like the ATnT and packed like an item.
Mercernary Camp
-Sea Dragon + The biggest monster under the sea. Murs tend to avoid them, as they have a tendency of being eaten by these magic-immune beasts... Casts Devour and has Spell Immunity
-Naval Cannon + The 'tower buster' weapon of choice. Has maddening range, but the cannon crew is a bit near-sighted...
-Mur'gul Slave + You always need a builder and repairer in these sorta games. Can Repair and construct Tidal Bunkers, Tower Bases, Wall Segments, and Tidal Guardians.
-Naga Royal Guard + 'I am Heavy Weapons Guy. And these are my weapons!' Casts Crushing Wave, Frost Bolt, Summon Sea Elemental, and Submerge.
-Naga Siren + Support spellcaster with Parasite, Frost Armor, and Cyclone.
-Mur'gul Assassin + Mur'gul Reavers with training in cloak and dagger tactics. Use Blink, Stealth, and Envenomed Weapons.
-Murloc Leper + A murloc wrapped in a festering cloud of desease. Send it on a solo mission into the enemy ranks to give Desiese Cloud to several of thier unit. Also knows how to Kaboom!, making a bigger mess as it's pluage stays after it dies.
-Snap Dragon + Fast Naga creatures with Submerge and Slow Poison
-Coatle + Flying Naga creatures. Can cast Abolish Magic.
-Zergling + Zerg Rush is in style with these little guys. One costs 1 gold, so store up and launch in droves. Can Frenzy.
-Doom Guard + These demons love a good brawl. Casts Cripple, War Stomp, Rain of Fire, and Dispel Magic.
-Blood Orc + Fel Orcs with a taste for desruction. Can use Frenzy and Pulverise
Old Tavern
-Goblin Sabetuer + Cunning Hero, adept at the use of explosives. Can learn Crazy Gernades, Standard Gernades, Make Time Bomb, Flame Strike, Reflexes, and Goblin-Assisted Homicide
-Naga Enchantress + Mystical Hero, who can pacify creatures nearby with her enchanting dances. Uses Samba of Silence, Perky Step, Slow Dance, and Motivational Performance
-Naga Incursor + Warrior Hero, known as one of Ashara's trusted soldiers. Can enact Capture, Command Aura, Zantetsuken, and Tsunami
-Naga Royal Guard Commander + Warrior Hero, who oversees the other guards. Can cast Crashing Wave, Frost Blade, Summon Sea Elemental, and Dark Depths
-Naga Warqueen
-Murloc Dreamcaster + Mystical Hero, a master of dreams and energy. Can cast Sleep, Brillience Aura, Mana Drain, and Nightmares
-Mur'gul Ocean Seer
-Murloc Shadow Assassin + Cunning Hero, heralding all the way from Ashenvale to join the fight. Has permanent Stealth, Fan of Knifes, Poison Blade, Escapee!!!, and Bad Karma... for You!
-Balrog + The only SuperHero Available widely, this guy costs 2000 Gold, but is worth the investment. He attacks with a flaming blade and uses other fire spells: Flame Strike, Flame Breath, Pheonix, Avatar, Inferno, Volcano, and Firestorm.
Footie Heroes
-Sniper
-Marine
-Stealth Assassin
-Death Sheep
-Woah!
-Falcon
-CattleBruiser
-Jaood
Allience Heroes
-Human and Nelf Heroes
Horde Heroes
-Orc and Undead Heroes
Nutral Heroes
-Naga Sea Witch
-Pitlord
-Beastmaster
-Pandaren Brewmaster
-Dark Ranger
-Firelord
-Goblin Tinker
-Goblin Alchemist
Etc. Heroes
-Archimonde + Uses Dark Portal, Rain of Chaos, Bash, and Finger of Death
-Garithos + Uses Holy Light, Shockwave, Devotion Aura, and Avatar
-Admiral Proudmore- Uses Monsoon, Divine Shield, Endurance Aura, and Tornado
-Sylvanis the Ranger + Uses Scout, Cold Arrow, Trueshot Aura, and Starfall
-Balnazzar + Uses Finger of Pain, Rain of Chaos, Sleep, Vampiric Aura, and Earthquake
-Detheroc + Uses Carrion Swarm, Sleep, Shadow Strike, and Death and Decay
-Illiden + Uses the same skills as a Demon Hunter, but hey, the imtimidation factor! Uses Mana Burn, Imolization, Evasion, and Metamorphisis
-Mannoroth + Uses Shockwave, Thunder Clap, Reincarnation, and Earthquake
-Gul'Dan + The warlock himself has come to challenge the temple. Uses Chain Lightning, Rain of Chaos, Feral Beast (Fel Spirits), and Doom
-Ghost + The ghosts who guarded the Horn of Cenarius have wandered since thier defeat... Uses Tangling Roots, Blink, Thorns Aura, and Tranquility.
-Akama + Uses Stealth, Chain Lightning, Feral Spirit (Fel Spirits), Shadow Strike, and Reincarnation.
-Kil'jaeden + Lord of the Leigon, he has come here in rumors his failed agent has come... Uses Dark Portal, Rain of Fire, Incinerate, and Finger of Death