Since I have only played Overlord: Raising Hell and Overlord 2 from start to finish I will be going into more detail about these games. While I only give a brief overview of the other 2 games.
The first Overlord game is the only game in the series to have DLC content which continues on from the original game, so when Overlord: Rising Hell was released on PS3, it contained both the full game and it’s DLC. The story goes: the original Overlord was killed by eight heroes, the last of which was badly injured and left to die after the raid of the Dark Tower. After the Overlord’s demise the surviving heroes following the lead of the Wizard who brought them together to purge the lands of evil, managed to convince the them to loot the Dark Tower and follow the 7 deadly sins. We are introduced to characters such as Melvin Underbelly, who follows the path of Gluttony, and Sir William the Black who lives the ways of Lust. The other heroes follow the rest of the deadly sins until they are corrupted by their own power and wealth and believed they were better than everyone else.
To help you along the way of becoming the most devilish person in the known lands, you have minions you can control and help you battle anything and everything along the way and Gnarl, who has more intelligence than the rest of the horde. The Minions that are sent into battle with the Overlord are stupid and only have one thing on their mind..... and that’s sheep. The Minions do whatever the Overlord commands them to do although in some situations they do just go off and fight anything that is consider a threat towards their Master.
The Browns are the first tribe you have access to. The Browns are the strongest minions you have access to, as they are general fighters, they will wear any armour and wield any weapon this could range from wearing a bucket on their heads and wielding a broom as a weapon until they find better equipment to use. The brown minions can’t go through water, fire or poison so to take over the lands they need help.
The Reds are second tribe which can be used but you have to find the red hive before you can use them. The Reds are not as strong as the Brown but when the Reds work together they are a powerful force where they can set fire to your opponents. The Reds can walk through fire and can be used to absorb fires.
The Green are the third tribe which can be used but you have to find the Red Hive before you can use them. The Greens are stronger than the Reds and are used for stealth attacks. If the Greens stay still or are placed at a place marker they will go invisible and will stay invisible until commanded or someone is foolish enough to walk past them. The Greens poison they enemies and do more damage to enemies but only if they are attached to the enemies back. The Greens can walk through poison gases and absorb poison clouds.
The Blues the fourth Minion that you can use but once again, you have to find the hive before you can use them. The Blue are the weakest of the tribes, and don’t fight unless they are ordered to fight by the Overlord. The blue minions are the only minions who can resurrect minions who have fallen in battle. The Blues are the only ones that can swim and use magic abilities to fight elves.
With the horde of Minions by your side you travel to place to place to pillage and take back the lands. Along the way, you find your Mistress who help spends your money on updating the Dark Tower. Some of the places you can visit are Mellow Hills, Heaven’s Peak and Evernight Forest, to name a few. Each area has tasks for you to do, and these tasks can range from recovering food for villagers who live in the small village of Spree. But, when you are doing these tasks you have a choice of being evil or really evil, so when you are recovering the food for the Spree villagers you can either take the food for the minions or you can let the villagers of Spree have it. Like most games where you have a choice of being good or evil it can affect your abilities, for example the magic you can use.
Overlord 2 continues on from Overlord: Raising Hell where you control "Overlad" who later eventually becomes the new Overlord. Overlord 2 controls exactly like the first game with some improvements, the Overlord can take control of a minion who can lead the horde of minions over an area where He cannot follow because of His size. The Minions can be in disguise, so they can sneak into a camp and cause more mischief and mayhem along the way.
The 3 Minion tribes now have access to animals which can be mounted. The Browns can ride wolves, while the Reds ride salamanders and the Greens ride spiders. When the "Overlad" becomes the new Overlord, the gamer has 2 choices to make, either dominate or destroy anyone who opposes you.
These games tell the story of the 1st Overlord with this game being on the Nintendo Wii, the storytelling is based on a fairy tale. With the Wii having motion control you can shake up the minions until they explode so the brown minions explode with a huge impact, the red minions explodes into flames that ignites nearby enemies, the green minions explodes with a green poisonous gas and the blue minions enhances all the minions and they will be resurrected when they are defeated. While in Overlord Minions you control 4 minions called Giblet (Brown), Blaze (Red), Stench (Green) and Zap (Blue) and you control the minions by using the touch screen on the Nintendo DS, so with this game the player is actually the Overlord.