What to play with really bad GPU?

Terraria definately

OpenTTD

Man, come on, i lived with a Pentium II @300mhz with 64RAM and 8Vram from 1998 to 2006 and you're crying cause you have a 512MB card?

mass effect

Dwarf fortress, command air naval operations, ageod american civil war, ageod revolution under siege, any hps simulations game, smolensk 41 is my favourite, harpoon commander edition, gary grigsby war in the east, war in the pacific admiral edition, command ops battles from the bulge etc

Hey that's nearly the equivalent to a 9500 GT, you should be able to play a few games, something like Assassins Creed 1 should work, pretty much anything released around those years should do the trick. Hell just look for "[gamehere] gameplay Geforce 9500GT/GT210"

Last game i played with that GPU (9500GT) was GTA IV if i'm not mistaken, ran fairly well at 1024x768 or 1280x720.

Counter Strike 1.6!

Solitaire, with real cards

If your CPU is sturdy enough, you could take up learning Dwarf Fortress.
Failing that, learn and play Nethack.

There is always the favourite fallback of Gamma Brothers. If your card can handle it, Startopia is a godsend. More modern games like Don't Starve and Binding of Isaac are good fallbacks, and 2D-centric adventure games like Broken Sword should do the trick. It's not all that hard to stumble across good games for lower-end computers, it's just that you're perhaps used to sharper graphics.

I used to run a 7600GS with 512MB for quite some time (too much time actually), seems a bit comparable. I mostly played BF2 and C&C Generals on max or nearly max settings on it. Also ran stalker SoC on mediocre settings on it (not 1080p, probably 720p ish). I also recall playing CoD:MW on it. Not on high settings, but decently playable for me.

Other than that, most indie games are not that demanding.

You might not be able to play the newest releases outside of Indies, but if you play games from some years ago you should still be able to get some nice games to play without feeling you are playing dos games again.

Age of Empires II, if you like strategy games.
If you don't like strategy games, Age of Empires II.

Cave Story, and 90% of other indie games or games from the early 2000's and before that I would say.

Your Nvidia software, if you have explored it a bit, has a list named "Compatibility with Games". In that list each game has a status attached to it and telling you whether you can play that certain game or not.

Stop asking stupid questions. The answer was in front of your face.

So you have a GeForce 210, and I have a Radeon 4670. A very quick 3DMark 06 check tells me your GPU is roughly 50% faster than my GPU.

You have successfully played Borderlands 2, Skyrim, Portal 2, Dragon Age, etc, investing hundreds of hours into those games. Speaking of hundreds, you also have hundreds of unplayed games.

Giveaway or not, I have no idea what you're complaining about and why you can't find a single game to play in those afore-mentioned hundreds that you haven't yet touched.

Dwarf Fortress. This game has no graphics and brings lots of fun. It's like 2D Sims/SimCity/Lord of the Rings/7 Dwarves game with procedurally generated world with its own history and thousands of characters.

Minesweeper / Solitaire. And Fortix of course.

Delta Force

I'm playing Guacamelee! on my wife's laptop (specs are not that good) and it loads fast and runs smooth and is a lot of fun!

GOG.com

With G210M i played DiRT 2 with good graphics and that was smooth. I can't really remember what did i play with that but generally i couldn't play anything really good. For example, games uses Unreal Engine 3 released before 2010 were good enough. Updated Source Engine was terrible (i mean Portal 2-CS:GO Source Engine). You can always play good games from old era like Hitman 1-2, Blood Money; Titan Quest, Test Drive Unlimited, American McGee's Alice etc. but it depends on your RAM and CPU as well (mine was Centrino2, that's why gaming became really crap those times). Also i played Oblivion and Fallout New Vegas on G210M, they weren't so smooth but good enough.

I hope that info will help you.

edit: Also Carpe Fulgur games like Recettear, Chantelise and so on... Ah, Fortune Summoners also an option.
On GOG.com, my favorites were Outcast, Shogo: Mobile Armor Division and Guilty Gear X2. Also try Torchlight if you didn't play it.

Psychonaunts, Gun, MGS1, Bioshock 1 and 2 (they don't require much), Torchlight 1 and 2, Sam and Max, GTA SA, Borderlands etc :)

Ah, install Onlive, and play every game they have there, for 30 min :))

plays MUDs, especially cyberpunk ones. There can be no game more cyberpunky than a MUD.

Heroes of Might and Magic 3

You need to be more specific with your gpu and other system specs.