Rather than flooding your post with a wall of text, and having you go to investigate videos of game play anyways, , go to youtube and enter:
"games for 512mb graphic card"
in the search results. This will give suggestions AND allow you to see gameplay at the same time to see if the game is right or you.
A few examples:
Top 10 Games for 512 - 1024 MB Graphics Card | Part 3:
View: https://www.youtube.com/watch?v=HL6uZjaXPuc
TOP 200 Games for Low SPEC PC (512 MB VRAM / 1 GB VRAM / Intel HD Graphics):
View: https://www.youtube.com/watch?v=HxdjUiN5fMo
You can also enter searches for "games for 256mb graphic card"
NOT entering suggestions for the usual popular shooter royale games such as Fortnite, . Assuming you have already done your own research there.