I was thinking of this and metropolis street racer on the dreamcast had a feature that used the internal clock of the dreamcast to calculate the time zone for the city’s you race in eg morning race in tokyo but your next race is a night race in san francisco,
another game(s) would be metal gear solid on the ps1 where psycho mantis would read your memory card for any konami games made before mgs or in mgs twin snakes on the gamecube and comment on them.
There are a few games that immediately pops into my head.
System Shock took two genres, FPS and RPG, and combined it into one game. As far as I know, that was the first time you saw games crossing different genres into one. It made for absolutely epic games. It took years after System Shock for other games to do the same.
Black and White took artificial intelligence to a place where no other game has ever gone before, and not many since either. The fact that you could not directly command your creature, but merely influence it was amazing. It was way ahead of its time as well. By today’s standards it may be clunky, but was revolutionary at the time.
Myst must also be mentioned. It was probably the first real successful walking simulator, and only years and years later did other games follow that same formula that it perfected.
thief. The first person stealther (where you aren’t necessarily meant to kill everyone on the map) was born.
City of Heroes, first MMO where you could play with friends no matter what your level. This was in 2005, way before WoW, GW2, ESO ever even had the idea.
Wolfenstein 3D. I knew exactly what they were getting at with that game:VR without a headset.
well thats what 11 year old me though anyway.
It was amazing at the time. just pure amazement.
Dune 2 — the great-grandpappy of the RTS genre. It didn’t have group select or macros, a skirmish mode, or multiplayer, but it did have a three faction system which StarCraft would eventually expand upon.
Wing Commander / Strike Commander — Chris Roberts and his team created combat flight simulators that revolved around a larger narrative.
Karetaka / Prince of Persia — Jordan Mechner used rotoscoping to create smooth animations for character sprites.
Quest for Glory — Corey and Lori Ann Cole created an RPG adventure series where your save file is carried over from one game to the next. I don’t think they carried over decisions, but your character progress was carried over and gave you an instant kind of “New Game+” mode.
Grail Quest (1989) — Borrowing heavily from LucasArts’ SCUMM system, I remember this game featuring excellent graphics and sound for the time. It’s kind of like Myst meets verb-driven adventure puzzler, meets rudimentary RPG. This was old-school: You can consume or throw away essential items needed to solve puzzles and die pretty easily in fights.
Diablo — Revolutionised the hack 'n slash genre and spawned a whole new subclass of loot-driven games.
Street Rod — While Accolade’s racing games like Test Drive predate it, Street Rod let you buy and upgrade cars, then race for money or pink slips to get better cars and parts with which to race more difficult opponents. This was in 1989, years before Need For Speed.
If I had to choose a single developer/publisher as the most innovative of all time, Sierra is the first name that comes to mind. A company like Blizzard might rival it, but Sierra was just responsible for so many excellent, innovative games, I think it would beat out all comers.
I think Half life 1 was also published by sierra if im correct
Indeed. F.E.A.R. and Homeworld too!
So many of my favourites on that list. 
Strike Commander made a few major technical innovations as well. For one, it was the first game to implement industrial flight sim techniques such as Gourard shading and texture mapping on the PC. It also replaced sprite based ingame models with fully 3D ones; this was 1994, remember!
Speaking of Half-Life, I think it deserves a mention for completely revolutionising the way shooters were made. Before Gordon Freeman came along it was all run maze, kill boss, find key, go to next level, etc. Half-Life turned the FPS into an awesome cinematic experience. It’s one of the most brilliant games ever made.
Star Wars Galaxies was 2003 and you could play with friends regardless of level. Maybe not everything, but you could hang out and play music/dance in the cantinas.