I'm a mud-hopper, and maybe that's the reason I got the impression that I did from this mud; on the other hand, I know other people that feel the same way. Xyllomer tries to do many different things all at once, and whether it succeeds or falls flat on its face is entirely to the judgement of the player.
Whether your opinion is positive or negative, you'll find many people to share your view. Xyllomer seems to be one of those 'love it or hate it' things where each member of its audience unfailingly ends up either as a converted zealot or as an estranged deserter. I find myself the latter.
The mud in itself is basically a never ending player-killing war between two main guilds and a few neutral guilds on the sidelines. The "good" guild is on the low end of the power scale and easy to join by newcomers to the game. The "evil" guild is very much on the high power end of the scale, and is reserved only for long-time players who have achieved out-of-character recognition by the administration or other players in power.
Added to this is, of course, the roleplaying committee which strives to keep everything in-character and relatively interesting, and firmly maintains over and over that there is fun to be had in the game outside of combat. In the end though, roleplaying tends to bottom out at not speaking out of character and saying "Let's go hunt" instead of "Let's go get some XP".
On top of this is the world, which is nice, and includes several dungeons which are fun the first time around, and mining, herb-gathering, and trading mini-games.
As correctly pointed out by a previous reviewer, the mining, alchemy and trading "guilds" are not real guilds at all, but rather crafting professions which you can take on top of your actual guild. It is common to have players try to pass these as full guilds when confronted by criticisms on the game's lack of the same. They are not.
Xyllomer does a few things in an entertaining way, however, in the end I found it does none of them particularly well. There's good player combat, but Carrion Fields and Achaea do PK much better. There's roleplaying and ambiance, but Armageddon and Isildur do those much better too. There's exploration and dungeons, but Discworld and Retromud are superior on that. There's crafting and minigames, but DartMud pretty much takes that cake. There's something to be said for trying to be everything to everyone, but if you have a specific preference for any of these, chances are there's a better mud out there for you.