| PC/MS-Windows pack. |  A Lot of Universes Model 1303370 | 20?? | Steam Valve Corp. |
| PC/MS-Windows pack. | A Lozenge Model 1354100 | 20?? | Steam Valve Corp. |
| PC/MS-Windows pack. | A Lullaby of Colors Model 992960 | 20?? | Steam Valve Corp. |
| PC/MS-Windows pack. |  A Mage Reborn Demo Model 2004620 | 20?? | Steam Valve Corp. |
| PC/MS-Windows pack. | A Mage Reborn Model 2004610 | 20?? | Steam Valve Corp. |
| PC/MS-Windows pack. | A Magical High School Girl Demo Model 556660 | 20?? | Steam Valve Corp. |
| PC/MS-Windows pack. | A Magical High School Girl Model 555630 | 20?? | Steam Valve Corp. |
| PC/MS-Windows pack. | A Maiden Astrologer Divines the Future Model 2162950 | 20?? | Steam Valve Corp. |
| PC/MS-Windows pack. | A Marble's Muse Demo Model 1505340 | 20?? | Steam Valve Corp. |
| PC/MS-Windows pack. | A Marble's Muse Model 1427780 | 20?? | Steam Valve Corp. |
| PC/MS-Windows pack. | A Mars Journey - Redturtle Model 936000 | 20?? | Steam Valve Corp. |
| PC/MS-Windows pack. | A Mass of Dead Model 269630 | 20?? | Steam Valve Corp. |
| PC/MS-Windows pack. | A Match with a Succubus Witch Model 1990830 | 20?? | Steam Valve Corp. |
| PC/MS-Windows pack. | A Matter of Murder Model 510040 | 20?? | Steam Valve Corp. |
| PC/MS-Windows pack. | A Matter of Principle Model 2210210 | 20?? | Steam Valve Corp. |
| PC/MS-Windows pack. | A Matter of Time Model 974310 | 20?? | Steam Valve Corp. |
| PC/MS-Windows pack. | A Maze Fox Model 1802430 | 20?? | Steam Valve Corp. |
| PC/MS-Windows pack. | A maze in Citadel Model 1101630 | 20?? | Steam Valve Corp. |
| PC/MS-Windows pack. | A Mazeing Tower Defense Model 683080 | 20?? | Steam Valve Corp. |
| PC/MS-Windows pack. | A meadow Piece Demo Model 1085980 | 20?? | Steam Valve Corp. |
| PC/MS-Windows pack. | A meadow Piece Model 964100 | 20?? | Steam Valve Corp. |
| PC/MS-Windows pack. | A meeting of dreams Model 2179560 | 20?? | Steam Valve Corp. |
| PC/MS-Windows pack. | A Memoir Blue Model 1497450 | 20?? | Steam Valve Corp. |
| PC/MS-Windows pack. | A Midnight Village Story Model 1395480 | 20?? | Steam Valve Corp. |
| PC/MS-Windows pack. | A Midsummer Night's Choice Demo Model 520160 | 20?? | Steam Valve Corp. |
| PC/MS-Windows pack. | A Million Conquests Model 1129210 | 20?? | Steam Valve Corp. |
| PC/MS-Windows pack. | A Million Hits Model 940050 | 20?? | Steam Valve Corp. |
| PC/MS-Windows pack. | A Million Lightyears Beyond Model 1833870 | 20?? | Steam Valve Corp. |
| PC/MS-Windows pack. | A Millionaire's Story Model 2249800 | 20?? | Steam Valve Corp. |
| PC/MS-Windows pack. | A Mining Game Model 659500 | 20?? | Steam Valve Corp. |
| PC/MS-Windows pack. | A Mirror Puzzle Model 1655420 | 20?? | Steam Valve Corp. |
| PC/MS-Windows pack. | A Modest Legacy Model 1858090 | 20?? | Steam Valve Corp. |
| PC/MS-Windows pack. | A Monster's Expedition Demo Model 1326610 | 20?? | Steam Valve Corp. |
| PC/MS-Windows pack. | A Mortician's Tale Model 578720 | 20?? | Steam Valve Corp. |
| PC/MS-Windows pack. | A Most Extraordinary Gnome Model 2089710 | 20?? | Steam Valve Corp. |
| PC/MS-Windows pack. | A Mountain of One Model 2230720 | 20?? | Steam Valve Corp. |
| PC/MS-Windows pack. | A Moustache in the House 2 Model 1877820 | 20?? | Steam Valve Corp. |
| PC/MS-Windows pack. | A Moustache in the House Model 1203770 | 20?? | Steam Valve Corp. |
| PC/MS-Windows pack. | A Murmur in the Trees Model 1475260 | 20?? | Steam Valve Corp. |
| PC/MS-Windows pack. | A Museum of Self & Space Demo Model 1566170 | 20?? | Steam Valve Corp. |
