When comparing Mark of the Old Ones vs Garry's Mod, the Slant community recommends Garry's Mod for most people. In the question“What are the best games on Linux?” Garry's Mod is ranked 43rd while Mark of the Old Ones is ranked 86th. The most important reason people chose Garry's Mod is:
Garry's Mod has a wide variety of [community made add-ons](http://steamcommunity.com/workshop/browse/?appid=4000), which deeply extends the games content and versatility. Pretty much, if you can think of it, someone has probably already made it.
Ranked in these QuestionsQuestion Ranking
Pro Unique, inverse kinematics-based control scheme that allows rarely seen freedom of control
By utilizing an inverse kinematics-based control scheme there is zero need for pre rendered animations for the character. It is animated real time.
Pro Immersive, HP Lovecraft-inspired aesthetic
Mark of the Old Ones has a HP Lovecraft inspired aesthetics and graphics with the protagonist being a tendril laden creature who traverse landscapes that look fitting for any lovecraftian themed title.
Pro Free of restrictive DRM
Without having DRM loaded into the game users can not only play the game without an internet connection but also play it on as many of their compatible devices as they like. On top of this it can also be shared with friends, just as one would have back before DRM existed.
Pro Tons of community made add-ons allows the game to continually grow
Garry's Mod has a wide variety of community made add-ons, which deeply extends the games content and versatility. Pretty much, if you can think of it, someone has probably already made it.
Pro The games mechanics and mods allow for ridiculously funny gameplay
You can do some really crazy things in this game thanks to all of the community mods available as well as the built in, in game tools. Pretty much any scenario can play out in the game, if you so desire. Of course the winning combination of funny tends to be when players are just goofing around.
Con Limited architecture support
Mark of the Old Ones has no plans to create or support a 32bit version of the game which will limited people who are still using older 32bit systems.
Con Previously free to download
Garry's Mod used to be a free download but it is now a paid game on the Steam store.
Con Tons of bugs
At least in earlier versions.