Does games that support windows8 work in windows 8.1. ?

Games that work on Windows 8 should work on Windows 8.1, from my understanding. The few games I've played on both Windows 8 and Windows 8.1 (Saints Row 2/Saints Row: The Third) have worked without any issue.

Thanks for the info

Many don't, due to problems with the DRM. Windows 8.1 broke Starforce and ActControl, so games that are using these DRM methods won't work in Windows 8.1 unless updated. Shouldn't be a problem with DRM-free games though.

Its rather amazing to see so many user issue threads on the matter of Windows 8 and 8.1. I don't recall seeing such things with Windows Vista or 7!

Haha. At least MS did ONE good thing! xD

From what I've seen so far most should work on 8.1 if they work on 8. I believe there is a compatibility mode added for 8 if you upgrade to 8.1.

Windows 8.1 does indeed have a compatibility mode for Windows 8.

That's because most people were content to leave their heads buried in the sand. With XP apocalypse a few weeks away, urgency to upgrade has skyrocketed.

Most of the new machines are sold with 8.1 already installed

I do not know if that is completely true.
There is an amount of time required to shed all of the older computers, so at the moment there are many PC sales companies dropping there last Win7 / Win8 computers for up to 50% off here in the UK. If you need to update quickly here I have seen many tower units and laptops with Win 8 going for around £200-300 with the same kind of spec as my computer which is only 2 1/2 years old. I have even seen some really nice spec towers going really cheap on eBay just because they are Win7 systems.

It makes me feel bad with how quickly the cost of computer parts drops off, it truly is a mugs game to keep up.

You were probably living under a rock at the time. There were complete sites dedicated to games compatibility problems.