| PC/MS-Windows pack. |  A Small Robot Story Model 753440 | 20?? | Steam Valve Corp. |
| PC/MS-Windows pack. | A Smooth Game (Unlike... Life) Model 2142100 | 20?? | Steam Valve Corp. |
| PC/MS-Windows pack. | A Snake In A Maze Model 1560050 | 20?? | Steam Valve Corp. |
| PC/MS-Windows pack. | A Snake's Tale Model 654810 | 20?? | Steam Valve Corp. |
| PC/MS-Windows pack. | A Snowman's Chance Model 2344640 | 20?? | Steam Valve Corp. |
| PC/MS-Windows pack. | A song in the void Model 746900 | 20?? | Steam Valve Corp. |
| PC/MS-Windows pack. | A Sound Plan Model 963470 | 20?? | Steam Valve Corp. |
| PC/MS-Windows pack. | A Space For The Unbound - Prologue Model 1201280 | 20?? | Steam Valve Corp. |
| PC/MS-Windows pack. |  A Space For The Unbound Demo Model 1268090 | 20?? | Steam Valve Corp. |
| PC/MS-Windows pack. | A Space for the Unbound Model 1201270 | 20?? | Steam Valve Corp. |
| PC/MS-Windows pack. | A Space Odyssey Model 1821510 | 20?? | Steam Valve Corp. |
| PC/MS-Windows pack. | A Special Place In Hell Model 2266370 | 20?? | Steam Valve Corp. |
| PC/MS-Windows pack. | A Spooky Teaparty Model 714520 | 20?? | Steam Valve Corp. |
| PC/MS-Windows pack. | A Squire's Tale Demo Model 1248600 | 20?? | Steam Valve Corp. |
| PC/MS-Windows pack. | A Squire's Tale Model 1248590 | 20?? | Steam Valve Corp. |
| PC/MS-Windows pack. | A Star of Chrome Model 1613300 | 20?? | Steam Valve Corp. |
| PC/MS-Windows pack. | A Steak Temple Panic - Chapter 2 - Welcome to Sanglinours Model 2129440 | 20?? | Steam Valve Corp. |
| PC/MS-Windows pack. | A Step Forward Demo Model 1760430 | 20?? | Steam Valve Corp. |
| PC/MS-Windows pack. | A Step Forward Model 1759720 | 20?? | Steam Valve Corp. |
| PC/MS-Windows pack. | A Step Into Darkness Model 578600 | 20?? | Steam Valve Corp. |
| PC/MS-Windows pack. | A Stickman Reality Model 889220 | 20?? | Steam Valve Corp. |
| PC/MS-Windows pack. | A Story About My Uncle Model 278360 | 20?? | Steam Valve Corp. |
| PC/MS-Windows pack. | A Story Beside Model 634410 | 20?? | Steam Valve Corp. |
| PC/MS-Windows pack. | A Story In Space Model 1300050 | 20?? | Steam Valve Corp. |
| PC/MS-Windows pack. | A Story of a Band Model 856450 | 20?? | Steam Valve Corp. |
| PC/MS-Windows pack. | A Story of Distress Model 791760 | 20?? | Steam Valve Corp. |
| PC/MS-Windows pack. | A story of vaccines & zombies Model 1496490 | 20?? | Steam Valve Corp. |
| PC/MS-Windows pack. | A Strange City Model 1564940 | 20?? | Steam Valve Corp. |
| PC/MS-Windows pack. | A Strange Hotel Demo Model 1605650 | 20?? | Steam Valve Corp. |
| PC/MS-Windows pack. | A Strange Hotel Model 1595950 | 20?? | Steam Valve Corp. |
| PC/MS-Windows pack. | A street cat's tale 2 Model 2356450 | 20?? | Steam Valve Corp. |
| PC/MS-Windows pack. | A Street Cat's Tale Model 1140570 | 20?? | Steam Valve Corp. |
| PC/MS-Windows pack. | A Street Story Model 1848360 | 20?? | Steam Valve Corp. |
| PC/MS-Windows pack. | A Stroke of Fate - Operation Bunker Model 372570 | 20?? | Steam Valve Corp. |
| PC/MS-Windows pack. | A Study in Steampunk - Choice by Gaslight Demo Model 421640 | 20?? | Steam Valve Corp. |
| PC/MS-Windows pack. | A Study in Steampunk - Choice by Gaslight Model 421630 | 20?? | Steam Valve Corp. |
| PC/MS-Windows pack. | A Summer with the Shiba Inu Model 916030 | 20?? | Steam Valve Corp. |
| PC/MS-Windows pack. | A Summer's End - Hong Kong 1986 Model 1111370 | 20?? | Steam Valve Corp. |
| PC/MS-Windows pack. | A Sun of Salt Model 919150 | 20?? | Steam Valve Corp. |
| PC/MS-Windows pack. | A Survey of Open Space Model 387470 | 20?? | Steam Valve Corp. |
