Doom 3 has been added (via GoG) and you have another 27 days to grab.
Been meaning to try this game, I remember when it was originally released on pc, I didn't like the games mechanics as you could only hold one item at a time either your gun or flash light, until the duck tape mod came out.
I was fortunate my pc could handle doom 3, AMD Athlon xp 2000 (1.6ghz), 512mb ram & Geforce 4 Ti 4200 with 128 mb.
Might give it ago as I own doom 3 bfg on both ps3 & xb360.