-TL;DR at Bottom-
Dungeons of Dredmor is simultaneously an addictively expansive roguelike with heaps of replay value and a disappointingly, shallow experience, and in this way, it is the World of Warcraft of it's genre. For it's price it absolutely is worth it, but at the end of the day you are left wishing the devs would have put a bit more thought into the game to create a solid experience.
At it's base, DoD is a turn-based dungeon crawler with painfully basic combat. You walk around rooms, meet monsters, left click them until they're dead. Occasionally you'll meet a situation where the enemies are statistically and/or numerically superior to you, at which case you must randomly spam offensive/defensive items and abilities at the issue until it's solved, and you really don't even have to pay much attention to exactly what it is you're using. It's just too inconsequential, regardless of the vast amount of options available to you. Increasing the difficulty or enabling perma-death somehow manages not to address this issue, it simply requires for you to pay more attention to the handful of mechanics that really matter. It might seem better for the first few floors of each playthrough, but regardless of settings and skillbuilds, the experience will degrade into the above mentioned simplicity by floor 5 no matter what it is you do, which is primarily due to XP and high level items being too abundant, leading to overleveling reducing the difficulty. Again, this stems from a lack of critical thinking employed in the basic game design, and while it'd be unfeasible to change anything at this stage of the game, it should have been taken much more seriously back in it's development infancy. The importance of a balanced experience distribution in an RPG game is one of the first things any old scrub with a couple hours of dabbling in RPG Maker learns, so it's downright embarrassing that Gaslamp Games took it so lightly.
So that's the core of the game. Why is this a good purchase then? Well the game has three factors that save it from itself; Humor, Content and Steam Workshop.
Humor, I would say, is DoD's greatest asset. Without it's presence, it would crumble and fall into the realms of indie shovelware, and it combines together with a feature that you can never go wrong with; content. So there's a lot of humor is what I'm trying to say. So the way this game works is, after presumably completing the short tutorial course, you start a new game and enter character creation. This process is unlike anything you've experienced before. You right off the bat get to chose a number of skill trees (1-8) for your Adventurer and decide your playstyle on the spot. The fun factor in this is all the various combinations made possible by this formula. Simply put, you can be a regular Melee user, a wizard or a mix of both, and if you'd like you can take the Warlock tree to help with that. Or not. It's very freeform, although hard to explain. Right off the bat you'll notice via the Skill Trees' descriptions that the game's funny. You have skill trees like "Battle Geology: Like all geologists, you can create earthquakes, armor yourself in stone, and petrify enemies. " and "Warlockery: Warlocks are wizards that really wish they were warriors. Or Rogues. Or cheesemongers. Anything but wizards, really. Their "spells" (as they are) serve to make them less wizard-like in a variety of ways.". If these two make you chuckle, or at least make you go "heh" internally, then you'll have an absolute blast once you actually plunge into the game. Every item name, item description, skill, spell, room, monster, monster description - really everything that's anything with words on it will have humorous dialogue that simply never gets ♥♥♥♥♥♥♥ old. Even monsters often make snarky comments from a list of a thousand or more phonemes. It ranges from low to high brow humor, references and even some memes here and there and it never feels distasteful or tired. If you're imaginative and weird, like me, you could also give a voice to all the text in your head, so that the Narrator from Trine 2, or hell, Jef Goldbloom says all the stuff, and it'll be all the more hilarious. And there's tons of this content, just tons and tons and tons. Rightfully so, because the game consists of 10-15 dungeons per run with each floor taking at LEAST an hour to complete unless you're leaving stuff unexplored.
This is where the Steam Workshop comes in. I personally don't recommend playing the game without all 3 DLC's installed AND the majority of the workshop content subscribed to and loaded up. The almost inexhaustible supply of content is the single one thing that can and will distract you from how shallow a game Dungeons of Dredmor actually is. When you're pretending to be a Vegan Necromantic Steampunk Knight and reading funny bits all the time, you don't care about gameplay. You'll be immersed into the whackiest, stupidest scenarios you've ever seen and you'll make it work. It's all novelty, but when there's this much of it, it works better than a real freaking game.
I should fleetingly mention that crafting and inventory management is a huge hit and miss. During some runs, I'll have patience and indulge in the hassle that comes with dealing with it. Other times I'll simply ignore 90% of the loot that spawns all over the floor and wish they put more effort into it. Ironically, while I'd say it's bad in this game, DoD's crafting is exactly what today's MMOs could use in order to make crafting actually freaking interesting. Because MMO's are MEANT to be timesinks, and items there would be worth the literal hours it takes to get specific equipment with noticable and snazzy uses like in DoD. As opposed to stupid junk you will NEVER pawn off on marketplaces, nor even think about using yourself. Oh and the music is loud and obnoxious but it grows on you.
One last, last thing; The gameplay is crap, alright, fine. But I should tell you that if you're of the particularly imaginative sort, there's plenty of room to create fun, self-imposed challenges that could alleviate this issue. On a basic example, you could stylize your character to only wield clockwork/steampunk styled items, which limits your equipment and arsenal. You can take concepts like this to much deeper levels that I can't really explain without you having played the game. It's like those weird people you see on GameFAQ's making up weird challenge run guides for Final Fantasy games. You can do that if that's your sort of schtick.
Gameplay: 2/5 - Shallow. Relies on your imagination to make it fun. Not for the casuals.
Replay Value: 5/5 - There's lots of ways to play and things to try and as a Roguelike, the game does excell.
Content: 5/5 - Thousands upon thousands of hilarious descriptions, names and phonemes is the game's primary source of fun.
Music: 3/5 - It grows on you, but nothing to write home about. Title song is catchy.
Art: 3/5 - It's pixelart. It's alright. Level art styles will leave you scratching your head sometimes.