| CollectiveCynic said: That doesn't make it innovative in any sense because it hardly brought anything new to the table, but that doesn't prevent it from being a classic game. The Half-Life series isn't particurly innovative either but they're outstanding games. Now excuse me, I'll running off before the Valve fanboys grab their torches and pitch forks. |
Where's my pitch-fork gone? 
Anyway, the original Half-Life was innovative. Quite simply for its time, nothing like it had been done. Bringing together a narrative; sequences that weren't all out action and instead, nicely scripted. People actually spoke to you for prolonged periods. No FPS game before had an introduction sequence that didn't feature shoving you straight into the action. Half-Life built tension by having you enter what was supposed to be another day at work.
Then there was the AI, it came out at a time when most FPS game AI either just shot straight at you or would end up running into walls trying to get you. In HL they actually ran for cover, flanked you and flushed you out with grenades.
To a lesser extent the shooting mechanics hadn't been done before either, at least not with as much polish as in HL. It added an extra layer of realism to FPS. Just compare the shooting mechanics to Sin or Quake II.
