Recommend a solo adventure game

[Fallen Seraph]

You should still give Half-Life 2 and the Episodes a chance. They are not your average FPS, they have interesting character, amazing plot and just overall extremely engrossing. They are not your normal, huge guns killing everything kinda game.

 

[Vigilance]

I'll add my voice to the chorus of Titanquest recommendations.

It's basically Diablo 2 set in the ancient Greek world.

Great game.

 

[Fallen Seraph]

Hmm... Also, just look around for old turn-based RPGs. You should be able to torrent a ton of them for your computer and run them fine: