| PC/MS-Windows pack. |  A Simple Request Model 2074050 | 20?? | Steam Valve Corp. |
| PC/MS-Windows pack. | A Simple Square Model 2251740 | 20?? | Steam Valve Corp. |
| PC/MS-Windows pack. | A Sinful Camp Model 1748050 | 20?? | Steam Valve Corp. |
| PC/MS-Windows pack. | A Single Step Model 1594990 | 20?? | Steam Valve Corp. |
| PC/MS-Windows pack. | A Sirius Game Model 392930 | 20?? | Steam Valve Corp. |
| PC/MS-Windows pack. |  A Sister's Journey Demo Model 2234830 | 20?? | Steam Valve Corp. |
| PC/MS-Windows pack. | A Sister's Journey Model 1730790 | 20?? | Steam Valve Corp. |
| PC/MS-Windows pack. | A Sketchbook About Her Sun Model 1611760 | 20?? | Steam Valve Corp. |
| PC/MS-Windows pack. | A Sky Full of Stars Model 745960 | 20?? | Steam Valve Corp. |
| PC/MS-Windows pack. | A Sleeper's Quest - A Labyrinth to Thee Model 1538170 | 20?? | Steam Valve Corp. |
| PC/MS-Windows pack. | A Slime And A Civil War Model 2216650 | 20?? | Steam Valve Corp. |
| PC/MS-Windows pack. | A Slime In Time Model 2214940 | 20?? | Steam Valve Corp. |
| PC/MS-Windows pack. | A Slit of Joy Model 1917320 | 20?? | Steam Valve Corp. |
| PC/MS-Windows pack. | A Slug's Dream Demo Model 2337700 | 20?? | Steam Valve Corp. |
| PC/MS-Windows pack. | A Slug's Dream Model 2303290 | 20?? | Steam Valve Corp. |
| 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. |
