This is actually my third time trying to finish Overlord believe it or not. I rented this game back when it came out on Xbox 360 and didn't get very far. A second time on PC, and now my third on PC. This is the furthest I've gotten in the game, about 2/3 of the way, but as time goes on the game ages more poorly than the last time I remember it. It was an early next-gen game for Xbox 360 so all eyes were on it and it was graphically impressive. It still looks great today and surprisingly runs amazingly well on PC without needing any fixes, but the game has a lot of issues.
Firstly, the game is incredibly tedious and the game has some very poor level design. There's no map, no objective marker, and the levels are very linear so even one of these things would have been so helpful. You blindly wander around these areas that all start to look the same trying to finish objectives. Now, the objectives can all be completed in any order for any area. Your main hub is a tower that you can customize and upgrade over time as you complete the game and from here you can fast travel to any level you have visited. The main gameplay mechanic is using the right analog stick and controlling your horde of minions to do your deeds for you such as carry items around and combat. You're very weak comparatively so entering combat isn't suggest unless you really need it. Again, not the worst problem.
What really starts to bore me is that sweeping your minions around works well enough minus some control issues when you have a straggler. The game favors the majority of the horde you end up controlling and stragglers sometimes won't join their brethren making things frustrating. You end up controlling four different minions. Reds, Blues, Greens, and Browns. Browns are your main grunt and do the most combat damage and have the most defense. Blues can enter the water, but can also revive minions. Reds can throw fireballs at a distance and put out fires. Greens can be sneaky and climb up larger enemies and also are immune to gasses and poisons. You end up spending almost half the game acquiring the three hives needed for the minions to open up new areas in each level. I constantly ran into roadblocks requiring me to backtrack and wander around a level until I ran into a new area I hadn't discovered. When I say the level design is bad, I mean piss poor. There are no memorable landmarks, just linear pathways that loop around, and turning around can literally look like two other directions you came from.
While navigation is a serious chore the use of minions is limited. There are no puzzles to be solved, just destroy everything in their path and make sure you use certain colors for certain enemies if need be. There are boss fights that are quite challenging, but then another major issue cropped up. You must horde and resource orbs to summon these minions, they aren't free. Certain enemy types will give you different orbs, but Browns are the most needed. I constantly had to go back to a level or two that had easy to mine sheep that gave me yellow orbs. I then had to exit the level and reload for the sheep to respawn just to get enough Browns to defeat a boss. If you're left in an area with no minions left you're pretty much screwed. You are never powerful enough to take out tough enemies alone and some bosses can only be defeated by minions. There are mana and health fonts you can sacrifice minions into, but they are far and few between so you really have to watch your health. Minions can loot stuff and find potions to help out a little, and this is the best way to acquire gold in the game to upgrade your weapons and armor.
Once you get used to the controls and gameplay loop you will really start to see how much aimless wandering you do where you aren't doing anything at all. I had to always keep a mental note of where a certain area was blocked and by what element so I could go back and progress and complete another mission. Progressing was somewhat satisfying but I spent 75% of my playtime wandering around these levels trying to remember where to go and figure out what part I hadn't discovered yet. Another issue I would run into is not having the right minions so I would then need to backtrack back to a spawn hole and get the right minion, but it doesn't end there. Let's say you have 20 Browns, but now need 5 Blues because an object is in water. I would backtrack to a Blue spawn point I remember, but you can't send back Browns in a Blue spawn point. I then had to back all the way back to the beginning of the area just to send the Browns back. This is stupid and tedious and there is so many quality of life issues that could have improved the game. Let me send back any minion into any spawn point. Also, why spawn points? They're so far and few between let me just summon them from the ground anywhere. I already have a limited amount based on the orbs I collect.
With that, all said, the game might be worth a look if you really love the humor in games like Fable or from the mid-2000's fantasy era. I also felt despite the game toting being evil I never felt truly evil. You can save people for rewards or kill them, but it doesn't seem evil. The game never went above and beyond this so I just felt like a misunderstood good guy the entire way. What? The visuals hold up, the control is cumbersome but doable, and the gameplay is unique, but the constant aimless wandering, lack of a map or compass, and poor level design lead to tedium and make the game just plain boring.