How Gaming Has Changed Since 9/11
1. Major Game Releases Were Forever Changed
Onto more specific game examples, as I mentioned earlier about MGS 2 being changed, and in Sons of Liberty, the game infamously ends slap-bang in the middle of New York City, seeing Raiden and Solidus Snake fight it out above Federal Hall.
In the original version, this was meant to be far more detailed, going through multiple iterations that would've included World Trade Centre imagery during the sequence on the Tanker, and later on, a more notably destroyed New York.
This latter scenario "had" to happen as Raiden and Solidus needed to get from Arsenal Gear to Federal Hall for the big fight (without the area being completely overhauled anyway), but the version that shipped simply had them fall off Arsenal while it was in motion, only to end up on top of the Hall itself.
Notably jarring, the devs were simply out of time, though more detail of the deleted scenes became available on the Document of MGS 2 bonus disc.
It's also worth noting that GTA 3 underwent some VERY last minute changes, as it was set to release only two weeks after 9/11 happened.
Being delayed a month to give Rockstar some breathing room, cop cars were changed from NYC blue and white, to black and white, explaining why blue and white cars were seen in early game screenshots. An entire mission featuring terrorists called "Love Hurts" was taken out completely, alongside NPC dialogue that could've been seen to reference 9/11 itself.
Lastly, in a move that could've nigh-on killed the game, one plane's flight path was altered so it went nowhere near the larger skyscrapers in the game.
Many have theorised this is why the Dodo was infamously unable to fly without specific hidden methods, but Rockstar have never clarified.