The biggest problem with Shadowrun is that it is based on Shadowrun. Why is that a problem? Because Microsoft's game goes out of its way to avoid telling any kind of story. While this is normal modus operandi for an action game, it's not very fair to fans of this epic and popular franchise that have begged for some kind of interactive entertainment. Obviously you can't please everyone when you mess with a beloved franchise, but it would be nice if the game pleased anyone even slightly interested in the source material... Perhaps if you stripped away the brand name and simply presented it as a vanilla action game there wouldn't be as much contention about the actual gameplay?
Wasted opportunity to please aside, Shadowrun's core Counter-Strike style gameplay can be fun, if not a tad bit shallow at times. Shallow because there's is just not enough meat on its bones. The game only offers a few game modes and nine or so maps to play on (there are three additional maps but they are smaller versions of some of the others), which get old after awhile. The single-player portion of the game is a series of tutorial missions that teaches you the basic and advanced techniques, using the game's buy system, game modes, tech and magic skills, weapon usage and the advantages and disadvantages of each race. After completing each tutorial, the player is given the option to test that freshly accumulated knowledge against computer controlled bots. The single-player is engaging enough the first time around but there's very little chance that anyone will return to it after learning how everything works.
Shadowrun does do a lot of things right. The sum of its parts are very well balanced; everything from technology, magic and even race bonuses are implemented in a way that provides a solution for every situation.
That balance begins with the choice of race and extends to the technology and magic. For example, trolls are big, strong and have a naturally high defense, but a dwarf can sap their magical essence, weakening their defense and making them vulnerable to attack. Elves are another race that are balanced well - they are fleet of foot and can regenerate health over time, but they don't have a lot of health to begin with and can be killed fairly easily.
This balance is at play with magic and tech as well. For example, you can resurrect an ally but the healer (you) is then inexplicably linked to the patient. When the healer dies, the patient will slowly bleed to death. There are dozens of examples of this kind of intricate balance that encompasses the entire play mechanic and it all works pretty well.
Much like Counter-Strike, there are many roles to play and many rewards that allow the player to mix and match skill and race to create unique characters that support all kinds of play styles. These skills and the weapons that compliment them can be purchased before each round begins. You earn cash by racking up kills, capturing the Artifact, healing team mates, etc. Those funds can then be used to purchase a myriad of magics, tech and weaponry (some of this is "activated" while some skills - like Smart Link - are automatic). There are magics that allow you to resurrect and heal and races that have large amounts of mana; there are techs that improve aiming and allow you to see through walls; there's even stealth technology that lets you hide and teleport through walls that are perfect when coupled with the one melee weapon in the game - the katana. Shadowrun is all about team work and finding a role that works for you - and those roles are numerous - from support, to scouting to infiltration and full frontal assaults.
The other core problem (besides the use of the Shadowrun brand) with the game is that matchmaking can take a lot longer than it really should. I'm not sure if this is because the game is the first to support cross platform play or because the matchmaking technology being used by Microsoft needs to be optimized, but searching and connecting to a game can be difficult sometimes. Once you find the game you want, it's usually goes well and without a hitch. But occasionally, some folks may experience connectivity problems, and the only real way to fix it seems to be by exiting and finding another game. Perhaps I am splitting hairs, or have been spoiled by the multiplayer goodness of other games like Battlefield Modern Combat, but multiplayer matchmaking needs some serious tweaking.