If you aren't looking for competitive multiplayer, these genres typically offer the best performance-to-fun ratio for 3GB RAM systems:
Indie developers often create games with low system requirements that offer deep gameplay:
: A legendary class-based shooter from Valve. While it has more content now, it remains playable on older systems, especially when using performance-boosting configurations like mastercomfig.
System Requirements: 3GB RAM
. It is extremely lightweight and offers endless strategy gameplay. Battle for Wesnoth