FREE TO PLAY low-spec games for ubuntu?

Hello! I have been looking for some low-spec f2p games and I have tried openarena, 0.A.D., AssaultCube, Sauerbraten, SuperTux2, R, Minecraft, SuperTux kart, Battle for Wesnoth (sorry if translated wrong, for some reason it says the title in fiish Taistelu Wesnothista) and Warzone 2100. I really didn't like them at all as either my FPS was low like in Minecraft and R (yes, I'm serious) or then they weren't my style. Especially in 0AD I had like 4 buildings and 5 women, 3 soldiers and I commanded my soldiers to go scout. Then a freaking army of soldiers came and r**ed my village and the AI had made practically a little country in there. Well, also I played UrbanTerror, I liked it very much, it looks like CSS. I'm looking for some more RPG style game, no I don't fancy for the graphics, but something with quests and stuff. Not 2D if possible. And definitely not tu-based. I'll post you the specs :

• AMD Athlon 2 Dual-Core M340.
• AMD Mobility Radeon HD 4530 /4570/545v (no idea what that means)
• 4 GB RAM
• 223.2 GB HDD