I think there is still room for improvement in games. They could add some of the innovation that came out years ago. Deformable terrain... so that you can take a 3 or 4 grenades & create your own fox whole. Ability to destroy objects walls etc... to create your own entrances in buildings ( if you have the right explosives). Add more wild life & people bugs etc... so when you crwal you see all the detail onthe groud you would see in real life.
What about the stuff that in that mercenary fps game where you could shoot the glasses of a guy or take out diff. body parts.
add all that & it would be a good start. When it come to gameplay ..gamers will take those old innovation & change they way the games are played.
Imagine being able to digg a tunnel outside a wall & sneek into an enemy base? or having the enemy discover the tunnel & toss a few grenades to make it colapse & take out 5 or guys.
I know all these things are demanding on hardware but ...I'm just tring to show that games have not hit the wall when it comes to improvements.