Innovation is a slippery slope as I largely believe innovation is really just the evolution of the same ideas we have already seen before and I think more credit has to go to the first person who does it right as opposed to just the first person to do it. As for gears specifically i say it took more of its inspiration from killswitch then RE4, but gears was the first game to nail the cover shooter perfectly so thats why  most ther 3rd person cover shooters since would say they took their inspiration from gears not killswitch, so id day its genre defining in the sense that it is the game that did it right and popularized the mechanic

This. No Man's Sky is the only game this gen so far that brings true innovation or as generation defining. It will change the idea of open world gamplay and sci fi type of games.

Yeah, I had this discussion a couple of times in a few places over the years. I was actually originally on the other side, for the record. But this is what I'm referring to generally: it's rare for there to be a general consensus on what a genre-definer is!

I can see where you're coming from, and it's quite a reasonable position to take, but in this particular case I've come to weigh the scales in favor of RE4. But I don't pretend that's some objective truth; in fact, as I said in a post after yours I started on the opposite side of the fence.

Taking a step back to the broader thesis though, I think it's illustrative that no one's really stepped forward for any of the other games listed in the OP. Perhaps that might change with time, but folks would be hard pressed to defend many of those examples. I'm especially looking at Bioshock...

Splatoon us

I disagree I highly doubt the idea of billions of planets and a universe would stick, cause its impossible to construct a proper story mode over a game spanning that big, that game still hasnt really sold me on its moment to moment gameplay as im still unsure what it really is, maybe a similar game on a smaller scale with like 8 or 9 fully sized planets to explore with a proper rpg storymode with multiple branching paths etc. would be really cool but we may be still a ways off before games get that ambitious

Oh, I don't know. I haven't really been following No Man's Sky, but Star Control II managed to have an excellent story mode even when featuring I-don't-know-how-many-thousands of planets, and that was in 1992. No Man's Sky seems more demanding on resources due to the increased tech from the past two decades, but having a story centered to core worlds, with the remainder being optional (and not equally bountiful) could work without too much trouble.

Besides, last I heard the game wasn't really going to have a story mode,  but just be a big sandbox.

You mean Kill Switch.  

It's funny, I remember playing Kill Switch and taking a really long time to get it down, as it was something totally new to me.  My friend went crazy over it and thought it was one of the biggest break-throughs in gaming.

I don't think it has to have a "proper story mode" to stick. Minecraft doesn't, and it basically created a genre.

I think something will come out for the Playstation VR that will do it.