| IronFall: Invasion (2015) | 1,122,032 | 330 |
| Ironheart (2020) | 11,319,930 | 496 |
| Ironlights (2020) | 513,983 | 225 |
| Ironseed (1994) | 8,941 | 37 |
| Ironseed 25th (2020) | 0 | 0 |
| Ironsight (2019) | 33,708,275 | 12,961 |
| IronWolf VR (2017) | 8,871,019 | 120 |
| Irony Curtain: From Matryoshka with Love (2019) | 516,474 | 591 |
| Irony Of Nightmare (2017) | 5,067,790 | 366 |
| Irotoridori No Sekai (2011) | 72,910 | 150 |
| Irrational Exuberance (2016) | 31,614 | 24 |
| Irritated Mind: Fear of Warehouse (2024) | 1,553,938 | 112 |
| Irritating Stick (1998) | 1,607,463 | 103 |
| Irukandji (2009) | 49,825 | 12 |
| Iruna Online (2008) | 7,744,214 | 6,565 |
| iRunner (2009) | 1,102 | 3 |
| IS Defense (2016) | 428,062 | 139 |
| Is this Game Trying to Kill Me? (2024) | 2,731,902 | 464 |
| iS: internal section (1999) | 34,306 | 62 |
| 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) | 20,554 | 38 |
| Isekai Rondo (2023) | 84,822 | 122 |
| Isekai Succubus ~My Genderbent Saga in Another World (2022) | 8,400 | 9 |
| Isekai Wet Dream (2025) | 1 | 1 |
| Isekai: Reincarnation in a New World (2020) | 0 | 0 |
| Isekaing: from zero to zero. (2024) | 965 | 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) | 88,407 | 217 |
| Ishido: The Way of Stones (1990) | 49,436 | 108 |
| Ishin no Arashi (1988) | 117,173 | 67 |
| Isis (1994) | 1,151,154 | 183 |
| Isla de la Muerte (2025) | 545 | 1 |
| Isla Sinaloa (2022) | 615,448 | 98 |
| The Island (1983) | 16,757,557 | 1,618 |
| ISLAND (2016) | 1,206,324 | 360 |
| Island 359 (2016) | 4,195,040 | 183 |
| Island Assault (2022) | 1,281,237 | 273 |
| Island Bender (2023) | 3,182 | 26 |
| Island Clicker (2024) | 12,916 | 16 |
| The Island Combat (2021) | 4,610 | 19 |
| 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) | 9,136,705 | 216 |
| Island Idle RPG (2022) | 188,865 | 10 |
| Island Keeper (2025) | 224 | 3 |
| Island Master (2023) | 29,786 | 78 |
| Island of Aito (2022) | 901 | 7 |
| The Island of Dr. Brain (1992) | 170,561 | 200 |
| Island of the Ancients (2022) | 17,484 | 36 |
| Island of the Lost (2021) | 130,163 | 128 |
| Island of Winds (2025) | 335,302 | 79 |
| Island Peril (1996) | 804,209 | 28 |
| Island Saver (2020) | 33,376,275 | 4,092 |
| Island Simulator 2016 (2016) | 130,482 | 4 |
| Island Time (2018) | 105,045,079 | 453 |
| Island Wars 2 (2004) | 28,436 | 40 |
| Island World (2021) | 101,173 | 98 |
| Island Xtreme Stunts (2002) | 430,197 | 239 |
| The Islander (2018) | 33,753,931 | 273 |
| The Islander: Town Architect (2019) | 155,823 | 34 |
| ISLANDERS (2019) | 15,287,098 | 2,316 |
| ISLANDS MIGHT FLY (2024) | 29 | 2 |
| Islands of Danger (1990) | 535 | 4 |
| Islands of Diamonds (2012) | 1,368 | 16 |
| Islands of Insight (2024) | 1,527,057 | 1,244 |
| Islands of Nyne (2018) | 21,166,302 | 977 |
