When comparing Dungeons of Dredmor vs Grim Dawn, the Slant community recommends Grim Dawn for most people. In the question“What are the best dungeon crawler games on Steam?” Grim Dawn is ranked 5th while Dungeons of Dredmor is ranked 10th. The most important reason people chose Grim Dawn is:
Basically you choose 1 class and select skills as you level up. At level 10 you can select a second class, which already gives you 5x5=25 character type possibilities. Each character has dozens of skills, plus you have this additional passive skill tree that you unlock through cleansing shrines. Then there is item customization with crafted "modifiers", adding additional unique stats and skills that you can use, all this adds literally to thousands / millions of character possibilities. Do you want to use a double weapon shooting lightning bolts? You can do that. Do you want to summon your creatures and support them with fireballs? You can do that as well, you can push it wherever you want.
Specs
Ranked in these QuestionsQuestion Ranking
Pros

Pro Combines punishing roguelike game mechanics with silly and satirical humor
The core mechanics of Dungeons of Dredmor are roguelike, but added on top of that is a silly humor that creates and endearing atmosphere.

Pro Several community mods were bundled as a free official expansion pack
In a testament to the quality of the Dungeons of Dredmor modding community, one official expansion pack consists almost entirely of user-created content. It was released for free, since they're not total capitalist jerks.

Pro Skill-based class system improves replay value
A character has seven selected skills, which effectively define that character's class: they have access to every skill selected, and no others. The base game contains dozens of skills, with many more available through both mods and official expansions.

Pro Configurable difficulty accommodates both casual and hardcore play
In addition to basic difficulty adjustment, the player can choose whether death is permanent (in classic roguelike style) or merely resets the current level. There is also a mode called "No Time to Grind" where experience points are increased from all sources, but in compensation, levels are smaller.
Pro Complex leveling system with thousands of possible builds
Basically you choose 1 class and select skills as you level up. At level 10 you can select a second class, which already gives you 5x5=25 character type possibilities.
Each character has dozens of skills, plus you have this additional passive skill tree that you unlock through cleansing shrines. Then there is item customization with crafted "modifiers", adding additional unique stats and skills that you can use, all this adds literally to thousands / millions of character possibilities.
Do you want to use a double weapon shooting lightning bolts? You can do that. Do you want to summon your creatures and support them with fireballs? You can do that as well, you can push it wherever you want.
Pro Great homage to old school ARPGs
This game is very dark, and grim. It harkens back to games like Diablo 2 or Titans Quest. While other ARPGs have come out since then, none have hit all the marks of what fans of the genre have been asking for. For those that wish for an updated version of Diablo 2, Grim Dawn is the game for them.
Pro Exploration
Pro Highly modifiable
Relevant in modern gaming because the community can keep products like this fresh and varied, even if the developers eventually decide to slow down their updates (which they have not!). The possibilities are great with modding, while the experiences in Diablo 3 and Path of exile are a lot more static.
Pro Drop-in co-op (online and local)
Co-op is pretty convenient as players can drop in and out of your gaming session at any time. This way there is no wasted time jumping out of ones game in order to find players to play with.
Cons
Con Minor interface issues
The interface feels very unintuitive with aspects such as having to change the default action feeling overly complicated and unecissary.
Con Only some builds are fun
There is a definite meta, with superefficient vs non-viable builds.
It's easy to mess up a build, and attribute and spec-bar points are non-respeccable (you can use a cheat editor, but devs want you to reroll a new char).
Con Difficult to move when fighting, especially when you are ranged
Con Static pre-rendered levels
This may cut down on replayability a bit as all the levels in the game are pre-rendered, meaning that each playthrough will have the exact same layout, making for something that can get tiring and too familiar. Similar games have gone with randomized levels, which can keep the game fresh. While Grim Dawn is meant to be a throwback to earlier games in the genre, some newer features found in more recent released would have been welcome.
Con Lots of trips to town
The majority of loot in the game can be useless, with odd stat restrictions or repeats of vendor items. This means the user will need to make many trips into town to sell it all off in order to have room for even more loot they will not necessarily need.
