This is not even revolutionary. It's de-evolutionary.
As we can see, the basic play is pretty much responsive and the controls are on slick with the character, and fighting your usual gimmick of demons and monsters seems pretty easy enough that a 8 year old (literally) can get on a immerse their selves easily into combat. Each class (only 3 main but with an alternate): the blademaster/templar, the engineer/hunter, & the evoker/summoner provide their own variations of combat along with differential skill trees. However, as you progressed later into the game, you find out more that each skills does not compensate each other and act only as requirements to the later, more powerful skills that are not actually powerful in proportion to the first tier of skills. Melee combat is fluid enough so that any close combat characters can get themselves in & out of a mob but there are occasional quirks here & there that makes me question whether the creature designs that you will fight against were actually rushed in the final weeks of the development period or ripped off directly from the demo released a month ago. The FPS mode is made simple enough for any range type class to roll over demons without having to suffer difficulties, but there's the kicker, it IS too simple. Recoil from rifles or pistols are only appearant in a character's accuracy and is indicated through your crosshair but does not affect your viewpoint; which brings me to the range combat aspects of the game. Like wise, fighting other enemies with ranged weaponry or abilities is more like playing duck hunt in a 3D format. Opponents will often stand still and take all potshots you throw at them or run away and repeat the same thing. Dodging simple flying electro bullets and fire blasts makes it for a lame game experience since there is no tactical thinking needed but only reaction time.
Character interaction with in-game NPCs is best described as inconcievably worse that Oblivion's funny dialogs, or nonexistant. All text chat and little, horrendous voice acting does nothing justice for this game.
Going to the bigger picture at hand, the main story does provide the player with a sense of direction but does not deviate into much of anything else. There is barely inaudible immersion into the storyline and the accompanying quests that does nothing but sends you out to kill a specific number of monsters, or collect this & this so you can get to that. There are the occasional slay the bosses quest but again it's very time consuming as each boss emits the same AI boundaries that ordinary demons possess: charging, swiping/shooting, rinse & repeat. This just leads you to running around in circles so the damn HP bar can go to zero.
The sound and scores that are placed into this game is what makes some parts of the game decent enough to travel through repetitive enviroments and abysmic level designs. The nature of the score pieces are a crossbred between orchestrated bass and disturbing techno, keeping the player a little bit interested in the near-absent plot and bland NPC conversations.
Graphic designs and buffering within the game itself is so last generation and provides only minimal dynamicy. Each level of detail, when ramped up in the options menu, only improves the bit-mapping qualities of characters and level enviroments, as any bump to texture improvement does nothing for it at all. Makes me feel I'm role playing Doom 3 in a apocolyptic London.
Finally, the backbone (or supposedly) of Hellgate: London lies in it's operating multiplayer contigency. However, the shift from free-to-play-locally to half MMORPG makes me wanna stick with D2 until the very end. The optional $10 a month subscription for a supposed to be free online gameplay will scare anyone dedicated to the Diablo series as several features will be locked until the monthly fee is paid. A game with great potential to be smacked by sudden changes at the end of its development life cycle will mar this forever more until a couple of major patch releases later.
Even Deus Ex & System Shock 2 would whack the *bleep* out this game old school.