Be evil and command your army of minions much like in Nintendo's Pikmin.
You play as a defeated evil man in armor, who has been put in a coffin after doing some evil deeds. Player is awakened by a group of small gremlins called minions and they take him to his ruined tower. Minions serve their Overlord to the death and it's now your job to use them in order to re-build your tower of evil. Game has a bright fantasy setting in it that resembles Lord of the Rings and the story is told through short cutscenes, but mostly by using great voice acting with subtitles.
Graphics are bright and they have that fairy tale like feel in them. It's nice to see lots of colors, although your goal is to be evil in that environment. Structures and buildings are mostly non-interactive and there are distinctive rails in which you can move, but there are enough space for you to do some exploration. Character models and animation are nicely done and especially your minions have a ton of personality. There's not that much music in the game, but sound effects and voice acting is plentiful. In the end audio visual presentation in Overlord is just what it should be.
Overlord himself is not that great to control, but his minions are responsive and with a little thinking there really is some strategy involved. Unfortunately micromanagement is done with the right thumbstick and this means that you have very little control over the camera. Most of the time this is not that big of a problem, but other times it can really be a pain. There are 4 different types of minions: browns are good at fighting, reds can absorb heat and have a ranged attack, greens can absorb poison and have a stealth attack, blues can swim. This brings a nice amount of variety, but it's also too hard to handle in a tight situation. A system resembling Star Wars: Knights of the Old Republic would have been nice, in which you can stop the action and then make your choices in a pace as you see fit.
Structure of Overlord is a lot like Nintendo's Pikmin, because in it you collected lost items of a spaceship and in Overlord you collect pieces of your ruined tower. There's a big world separated by loading screens and you can approach the objectives in any order. All of this is fine, but with no map what so ever the navigation is a lot harder than it should be and you can't set a glowing trail (GPS in GTAIV and Saints Row) to lead you to the right location like you can in Fable 2 for example.
Save system is awful and automatic. For some reason it saves almost only between different areas. This means that if you die after playing for 30 minutes in a single area you need to do it all over again. At times you can just leave the area every now and then to make the game to save your game, but other times you'll notice that all of your progress has seized to exist after visiting another area. Autosave is a good choice in linear shooters or driving games, but in a non-linear adventure game with multiple steps in every task it's just a bad design choice.
Overlord has its moments and it definitely has potential. Unfortunately there's no map, the save system is awful and sometimes you need to fight with the controls rather than against your enemies. Let's hope that future titles succeed a little better.