If you are having general performance issues, you are advised to ensure you have the latest display drivers installed, and check your hardware meets the minimum requirements. If this doesn't work, you can try turning down the graphics options, with a particular focus on the anti-aliasing, and uninstalling any user created mods.
If the game is not installing, or it's crashing on launch, then the post says you should try verifying your local cache on Steam, or simply reinstall the game.An odd issue arose where XCOM 2 was trying to launch with a resolution of 0x0. To get around this problem, you can go to the properties of the game in your Steam library, go to Set Launch Options, and type "-Windowed -SizeX=1280 -SizeY=720" into the box.
Firaxis says it will be continuing to support XCOM 2 with upcoming patches, so hopefully these bugs will be resolved soon.
Technical issues aside, IGN really likes XCOM 2. In our XCOM 2 review, we said thanks to its "great tactical combat, plus unpredictable maps and randomized object and loot, XCOM 2 is an amazing game." Matt Porter is a freelance writer based in London. Make sure to visit what he thinks is the best website in the world, but is actually just his Twitter page.