I have winxp x64 sp2. I run valkiria chronicles1, Dragon dogma(can't connect to servers)

The Bard's Tale's remastered & resnarkled update made it stop working on XP but the store page still lists it as supported. I think they made it 64-bit, so it might run on 64-bit XP.

It's possible to access the pre-update version and it works fine, but you need a beta key: TheBardsTaleUnsnarkled
Link: http://eo.steamhost.cc/steamcommunity_com/app/41900/discussions/0/1480982338947443057/

The demo for Mainlining works on XP SP3 32-bit, while claiming Win 7 as minimum. I don't own the game yet so can't check if the full game also works.

Thanks again @Vercinger

Realpolitiks works on XP SP3 32-bit, with caveats.

The first 2 scenarios work fully. The third scenario can be played fine, but trying to save causes a crash, and the resulting save is corrupted and unusable. Autosave doesn't crash, but trying to load the autosave causes a crash, so overall there's no way to save the game in the third scenario. As far as I can tell the problem is caused by the game running out of memory, the third scenario is more memory intensive. I can't test if the /3GB switch helps, because my OS BSODs when I try to start it in /3GB mode.

Also, exiting to the main menu or trying to load a (working) save from within an active game causes a crash, so the player has to restart every time they need to start a new game or load a save. Thankfully loading time isn't too bad. Presumably this too is caused by running out of memory.

Thanks @Vercinger

Cat on a Diet claims Win7 as minimum but works on XP SP3 32-bit.

Yeah I hear you, welcome to the group Darkhar!

Love this group is here, using a XP computer for gaming (Since my laptop is Linux 32, and there are also little games that work on it) and I have many troubles when it comes to know what can I install and what not. Hope I can contribute with games that run smoothly.

Glad to be here :)

Poly Bridge claims Win7 as minimum but works on XP SP3 32-bit.

Thanks for all the info Vercinger glad to have you aboard!

Also, damn the 1000 character limit on comments.

Finally, a note on Skyrim. XP officially supported, but the game tends to crash when modded. It's been a while so I don't remember if this is at all specific to XP or 32-bit systems or if it's just a general thing regardless of OS, but it doesn't hurt mentioning it. There's a thing called ENBoost which reduces crashing. Instructions here: http://wiki.step-project.com/ENBoost
Note that even though the instructions are for a specific overhaul mod, they apply in general. Also, I don't remember if this is the only thing I did to solve the problem, sorry.

XCOM: Enemy Unknown and its Enemy Within expansion claim Vista as minimum, but it's just the same thing as the last 3 - Vista+ DLL functions that can be used on XP with some work. As before, a fix is available. And since the game is no longer getting updates, there's no need to worry about updates screwing things up.
Instructions for Enemy Unknown - http://forums.steampowered.com/forums/showthread.php?t=2964408
Instructions for Enemy Within - http://eo.steamhost.cc/steamcommunity_com/app/200510/discussions/0/648811670593023950/
I can confirm Enemy Unknown works, but don't have Enemy Within.

Stellaris and Europa Universalis IV (and Hearts of Iron IV, but I haven't played that one so can't confirm) do not normally support XP, but only because they use some post-XP DLL functions. A wonderful reddit user named UncleVasya made a fix which allows them to run on XP, here: https://www.reddit.com/r/eu4/comments/4gu71r/cannot_start_eu4/d333tho/
Link to the fix itself: https://github.com/UncleVasya/EU4_WinXP_fix
Note that I haven't yet confirmed it works on the latest versions of either EU4 or Stellaris, but it should, at least on whichever versions are listed as supported on the github page.

Supreme Ruler Ultimate does not list XP support but had it for a while, before dropping it in an update. It still has an XP branch accessible via the Steam betas system, with the most recent version that supported XP. Relevant post here: http://www.bgforums.com/forums/viewtopic.php?f=72&t=24898
Full changelog to see the differences between the XP version (9.0.34) and the latest: http://eo.steamhost.cc/steamcommunity_com/app/314980/discussions/0/613939294507579733/

Crusader Kings 2 should still run on XP despite dropping it from the store page. However activating too many DLCs causes the game to crash when trying to save, as it tries to use more than 2GB of memory. But I haven't played it on Windows in over a year, so things may have changed. IIRC using a mod that cuts India from the map (assuming you don't mind not having it in the game) helped reduce memory use, but don't quote me on that, it could have been a fix for performance issues instead.
I'll post again if I reinstall it on XP.

Prison Architect claims XP support but it was dropped in a patch as it moved to 64-bit without updating the store page requirements. However, running the game in safe mode allows it to work on XP, as that version is 32-bit. I couldn't get a clear answer on what the differences are, but all that was mentioned was that safe mode disables mods and some visual flair. I couldn't find any other problems while playing either. XP SP3 32-bit.
However, that was a few months ago, and there's been a large update since, so I'll have to re-confirm first. I'll post again when I do.

OMG! This has been a thing for over a year and I never knew about it! Thank you for doing this!

I've found some games that work on XP despite the claims of the system requirements, and at least 1 that claims XP support but doesn't have it, but I never thought to write them down. I'll post them here as I rediscover them.

In the meantime, here's what I can recall right now:

There's a claim Evoland 2 works, but I can't verify it since I don't own the game. The claim is here: http://eo.steamhost.cc/steamcommunity_com/app/359310/discussions/0/527273452875009087/
I've left a message on the person's profile asking him to write here to confirm.

Cool, thanks for checking them out mrL0G1C.
If XP is already listed in the game's system requirements and it work fine there's no need to inform us. Although we do post a if a game has XP listed but doesn't work.

The following are tested into the gameplay:
Delver

And run nice on:
XP 32bit SP3, Intel Atom N270 single core 1.6ghz 2GB DDR2 ram, 1024x600 Resolution
Mobile Intel 945 Express Chipset Family, DirectX 9.0c

The following are tested into the gameplay:
Faerie Solitaire
Save Jesus
DungeonUp
One More Dungeon
Caster

And run nice on:
XP 32bit SP3, Intel Atom N270 single core 1.6ghz 2GB DDR2 ram, 1024x600 Resolution
Mobile Intel 945 Express Chipset Family, DirectX 9.0c

Ok I included HL2 because it doesn't have any system requirements, everything else you listed have XP in the sys. req. so they're not worth mentioing.

Here's how we roll: (to save you some time)
1) we mention the game if it does NOT have XP listed in the sys. req. but it still runs fine or needs some tinkering but works.
2) we mention the game if it DOES have XP in the sys req., but for some reason it doesn't work or needs some tinkering to work.

I have a 32bit Windows XP.

Btw you've got an SP3 32-bit machine right? Or some other variable?

I can tell some of them already have XP mentioned in the requirements. Imo if it's already listed it and doesn't cause any problems there's no need to list it. I'll check them all out though.

Elder Scrolls IV, Half-Life 2, Halo: Combat Evolved, Star Wars: Knights of the Old Republic, TF2, Half Life, Half Life 2, and Midnight Club 2. I have tested Elder Scrolls, Halo CE, TF2, and Half Life 2 the others came from a google search. Midnight Club 2 is supposedly XP exclusive, but I doubt it. When I said quite a bit I ment very little, also Loadout might work, I wil need to re-check it.

Yeah a game's a game imo, post away and thanks

F2P games are good, too =) Thanks for the help!

I have two old desktops that have Win XP, and Win Vista on them. If you either of you wanted I could say a list of games that ran fine on them. I did want to know if f2p games are to be excluded, as that would change my list quite a bit.

Glad to find this group! I was thinking of starting a curator on this topic if I hadn't found one in search. I'll post a list of games I've tested shortly