| Ironclads: American Civil War (2008) | 9,365 | 3 |
| Ironclads: High Seas (2009) | 51,312 | 3 |
| IronFall: Invasion (2015) | 1,122,483 | 334 |
| Ironheart (2020) | 16,464,994 | 739 |
| Ironlights (2020) | 513,991 | 225 |
| Ironseed (1994) | 8,941 | 37 |
| Ironseed 25th (2020) | 0 | 0 |
| Ironsight (2019) | 33,928,736 | 13,078 |
| IronWolf VR (2017) | 8,871,039 | 120 |
| Irony Curtain: From Matryoshka with Love (2019) | 516,559 | 592 |
| Irony Of Nightmare (2017) | 5,067,790 | 366 |
| Irotoridori No Sekai (2011) | 73,602 | 152 |
| Irrational Exuberance (2016) | 31,614 | 24 |
| Irritated Mind: Fear of Warehouse (2024) | 1,553,983 | 113 |
| Irritating Stick (1998) | 1,607,463 | 103 |
| Irukandji (2009) | 49,825 | 12 |
| Iruna Online (2008) | 7,754,934 | 6,581 |
| iRunner (2009) | 1,102 | 3 |
| IS Defense (2016) | 428,156 | 141 |
| Is this Game Trying to Kill Me? (2024) | 2,733,948 | 486 |
| iS: internal section (1999) | 34,456 | 63 |
| Isabella: Chasing Shadows (2024) | 193 | 2 |
| Isaiah 188 (2023) | 0 | 0 |
| Isaki Shuugorou no Keiba Hisshou Gaku (1990) | 1,009 | 5 |
| Isekai Cowboy (2023) | 766 | 5 |
| Isekai Frontier (2024) | 19 | 2 |
| ISEKAI FRONTLINE (2023) | 77,774 | 34 |
| Isekai Janken Hero (2023) | 2,769 | 6 |
| ISEKAI QUEST (2020) | 20,638 | 38 |
| Isekai Rondo (2023) | 84,833 | 123 |
| Isekai Succubus ~My Genderbent Saga in Another World (2022) | 8,453 | 9 |
| Isekai Wet Dream (2025) | 1 | 1 |
| Isekai: Reincarnation in a New World (2020) | 0 | 0 |
| Isekaing: from zero to zero. (2024) | 969 | 5 |
| isekizima: Ruins and Tails Journey (2025) | 74 | 5 |
| Ishar 3: The Seven Gates of Infinity (1994) | 73,313 | 137 |
| Ishar: Legend of the Fortress (1992) | 88,938 | 231 |
| Ishido: The Way of Stones (1990) | 49,568 | 114 |
| Ishin no Arashi (1988) | 117,266 | 67 |
| Isis (1994) | 1,151,296 | 183 |
| Isla de la Muerte (2025) | 581 | 3 |
| Isla Sinaloa (2022) | 615,448 | 98 |
| The Island (1983) | 17,231,884 | 1,699 |
| ISLAND (2016) | 1,206,354 | 360 |
| Island 359 (2016) | 4,195,065 | 184 |
| Island Assault (2022) | 1,283,702 | 285 |
| Island Bender (2023) | 3,182 | 26 |
| Island Clicker (2024) | 12,916 | 16 |
| The Island Combat (2021) | 4,652 | 20 |
| Island Dash (2017) | 0 | 0 |
| Island Days (2014) | 185,212 | 99 |
| Island Defender Jets (2022) | 0 | 0 |
| Island Flight Simulator (2015) | 776,319 | 118 |
| Island Hopper (1998) | 9,136,726 | 217 |
| Island Idle RPG (2022) | 225,222 | 11 |
| Island Keeper (2025) | 224 | 3 |
| Island Master (2023) | 29,956 | 79 |
| Island Notes (2025) | 22,213 | 20 |
| Island of Aito (2022) | 901 | 7 |
| The Island of Dr. Brain (1992) | 170,741 | 200 |
| Island of the Ancients (2022) | 17,484 | 36 |
| Island of the Lost (2021) | 130,171 | 129 |
| Island of Winds (2025) | 335,302 | 79 |
| Island Peril (1996) | 804,251 | 29 |
| Island Saver (2020) | 33,377,588 | 4,098 |
| Island Simulator 2016 (2016) | 130,482 | 4 |
| Island Time (2018) | 105,052,550 | 458 |
| Island Wars 2 (2004) | 28,436 | 40 |
| Island World (2021) | 106,894 | 101 |
| Island Xtreme Stunts (2002) | 430,774 | 242 |
| The Islander (2018) | 33,758,471 | 275 |
| The Islander: Town Architect (2019) | 155,823 | 34 |
| ISLANDERS (2019) | 15,711,216 | 2,381 |
| ISLANDS MIGHT FLY (2024) | 29 | 2 |
| Islands of Danger (1990) | 535 | 4 |
