Steam only gives me the choices of "thumb up," or "thumb down." I wish I could give this game a "thumb sideways."
TL;DR
If you *REALLY* liked the base game, then you will enjoy this. If you only kinda' liked the base game, then I wouldn't recommend you buy this. You honestly won't be missing out on anything.
I originally had an essay going for this review, but Steam only allows so many words, so I will try and keep this succinct.
*MINOR SPOILERS AHEAD*
OVERVIEW
The Black Labyrinth's aesthetics and level design are just as good as Amid Evil's. However, several "insta-kill-gotcha!" moments sprinkled throughout the game, combined with somewhat mediocre enemies, and annoying Gauntlet gimmicks help bring down what would have otherwise been a very nice return to the Amid Evil universe.
STORY
Like AE, this is super light on story. You are a wandering good-guy. Evil is bad, and you want it gone. You hear about a powerful artifact-weapon sitting at the end of a series of trials called the "Black Labyrinth." You show up at the front door, the Watcher lets you in. Surprise, surprise, this is a prequel so you know that you successful best the Black Labyrinth.
LEVEL DESIGN
The levels are just as well made in BL as they were in AE. The path forward is usually obvious, the secrets are reasonably hidden (most of the time), and the sense of scale and wonder, along with several memorable set-pieces (like giants flinging huge "spears" at you that you must platform off of to progress), really establish the high-fantasy feel that the game is going for.
However, there are several instances where it feels like the developers just flip the player the middle finger for no apparent reason. Like a giant Indiana-Jones-Stone-Ball that drops down at the top of a stair-case and insta-kills you if you hesitate for even a second (which you will, when you encounter it for the first time). Then there are the just-rare-enough-that-I-am-certain-they-are-deliberate use of spike traps which really throw me out of the experience, like when I ran over to grab an orange mana pick-up, only to discover too late that it was RIGHT next to an insta-death spike pit. Then, several levels are VERY darkly lit, making it very hard to see the ground and very easy to fall off the narrow walk-ways that have been placed within said dark areas. The Forges were considered some of the worst levels in AE, mostly for being dark and having so many narrow walk-ways. Why they included more of that in BL is beyond me.
Then, there is a bunch of really passive-aggressive graffiti painted on the walls throughout the levels. Some of the messages honestly didn't feel like they were jokes/in good fun, but I will let you be the judge when you read them.
ENEMIES
Most of the enemies are fine. They offer their own challenges and have neat, unique character models. However, I want to mention three in particular:
The archers fire projectiles like the Soleginaire in AE. The fire archers have arrows that burn on the ground and will damage you if you walk on them, and the captain archers have exploding arrows that bounce, wait for a second, and then explode. This requires you to keep track of the ground during frantic fire-fights so that you don't step on/near them and get hurt, which wavers between healthy challenge and downright annoying. The fact that they show up in groups and are often placed FAR away from the player only makes them more annoying. Again, I'm aware that the Soleginaire acted similarly in AE, but he showed up FAR less often than the archers do in BL.
The Disciples are a copy-paste of the Apostles. This is just kind of disappointing, since the rest of the enemy roster is totally unique. Not the biggest deal, but still.
The Knights of the Labyrinth are the worst of the bunch. They carry tower-shields which reflect your projectiles back at you. You either have to run round them and punch them to death, wait for them to attack and shoot their feat with pin-point accuracy, or target the ground behind them with a Celestial Claw shot and let the splash damage kill them. All three ways of destroying them are tedious. Thankfully, their attacks are easy to dodge and they move very slowly, so I just find myself running past them on my second play-through.
The most disappointing thing of all about the new enemies, however, is that I didn't notice any special quirks or fun interactions with their attacks like I did with some of the enemies in AE. For example, in AE you have the Lunar Deacon. The Deacon carries a knock-off version of the Whisper's Edge. When he shoots at you, you can shoot back with the Whisper's Edge and if the two projectiles meet mid-air, they will cancel each other out. That stuff is fun! I was hoping to see more of it in BL, but I don't think there is anything like it. Not that I noticed, anyway.
There are two new bosses in the game, that I will not spoil, though I will say that on harder difficulties their AI is either easy to exploit or infuriatingly difficult to work around. That is all I will say about them (they have nice character models and animations, though. They feel properly "epic").
WEAPONS
BL features the Gauntlets as a replacement for the Axe, and the Void Splitter as a replacement for the Aeturnum. The Void Splitter feels fun. A very solid alternative to the Aeturnum. Where the Aeturnum was like a grenade launcher with a long wind-up for it's attack, the Splitter is an instantaneous projectile attack that deals massive damage. I feel like the way the Splitter selects targets is a bit... "off" sometimes, but otherwise I'm genuinely happy with it.
The Gauntlets are a tremendous let-down. It functions IDENTICALLY to the Axe, except it has a button-gimmick attached to it. There are numerous purple buttons throughout the game which require you to equip the gauntlets and punch them in order to activate them. This creates some funny situations where you can, for instance, punch the stone block you are standing on across a room, but the novelty wears off rather quickly. Melee is still the worst way to fight enemies, and there is really no reason why I have to punch some buttons just to bounce myself up a cliff. I should really be able to just walk on top of many of these buttons like the regular blue buttons. When the Gauntlets were first previewed, I thought it was going to function differently in some way since it is a brand new weapon, but sadly that is not the case.
CONCLUSION
After 4 years I was expecting a bit more. Were it not for the various, niggling annoyances that jump up to bother you again and again I would honestly like this DLC a lot more. There really does seem to be a passive-aggressive tone to many of the design decisions, almost like they got sick of the player (but not the game) mid-way through development. I'm not sure. But, again, if you liked AE then for $12 you will probably like this.