https://www.cyberrun.net/
When I first heard about cyberrun I wrote it off because it was pitched as a sex game but it's actually more interesting then that. Technically it's not a MU* at all since it's entirely web based but it maintains a lot of the look and feel of a traditional MU*.
The setting is a cyberpunk setting that's very reminiscent of Eclipse Phase in how your character is essentially immortal and able to switch between bodies referred to as Idents(short for identity) which can raise all sorts of questions about who you actually are, especially combined with so called 'neuromods' which alter your perceptions. Idents can then be part of mutually-inclusive groups which explains how they make their living, martyrs who fight to the death for entertainment, cleaners cleaning up the minds of people who have been 'recalled' too many times, private security called 'boots' etc
The grid is somewhat sparse in detailed locations however players can make their own or be creative with those which exist.
The most novel feature of the game is a 'scene' system where you can write up scenes which you are interested in playing out and people who are interested can then apply to join those scenes with the option to enable 'prp' style narrative powers and skill checks.
The game also has a somewhat extensive consent system where you can allow other characters to make mental and physical changes to yours as well as a very exhaustive selection of preferences for what kind of RP you enjoy.
So if you want to play a game like Shadowrun or Eclipse Phase without having to deal with the actual rules of Shadowrun or Eclipse Phase, you could do a lot worse then give Cyberrun a try.