| Game Name | System |
|---|
| Undead Knights (Japan) | PSP |
| Undead Knights (USA) | PSP |
| Undead Line (Japan) | Genesis |
| Undead Line (Japan) [En by MIJET v20070903] | Genesis |
| Undeadline Denjuuki (1990)(T&E Soft)(Disk 1 of 3)(Program) | X68K |
| Undeadline Denjuuki (1990)(T&E Soft)(Disk 1 of 3)(Program)[a] | X68K |
| Undeadline Denjuuki (1990)(T&E Soft)(Disk 2 of 3)(Disk A) | X68K |
| Undeadline Denjuuki (1990)(T&E Soft)(Disk 3 of 3)(Disk B) | X68K |
| Under Defeat (Japan) | DC |
| Under Defeat (Japan) (GDL-0035) | MAME |
| Under Fire (1985)(Avalon Hill)(Disk 1 of 8) | Apple2 |
| Under Fire (1985)(Avalon Hill)(Disk 2 of 8)(Units and Scenarios) | Apple2 |
| Under Fire (1985)(Avalon Hill)(Disk 3 of 8)(Extension 1A) | Apple2 |
| Under Fire (1985)(Avalon Hill)(Disk 4 of 8)(Extension 1B) | Apple2 |
| Under Fire (1985)(Avalon Hill)(Disk 5 of 8)(Extension 2) | Apple2 |
| Under Fire (1985)(Avalon Hill)(Disk 6 of 8)(Play) | Apple2 |
| Under Fire (1985)(Avalon Hill)(Disk 7 of 8)(Maps) | Apple2 |
| Under Fire (1985)(Avalon Hill)(Disk 8 of 8)(Save) | Apple2 |
| Under Fire (Japan) | MAME |
| Under Fire (US) | MAME |
| Under Fire (World) | MAME |
| Under Pressure | Amiga |
| Under Pressure (1992)(Electronic Zoo)[h Cynix - Quaser] | Atari ST |
| Under Pressure (1992)(Electronic Zoo)[h Cynix - Quaser][a] | Atari ST |
| Under Pressure (demo-playable)(1992)(Electronic Zoo) | Atari ST |
| Under Siege (Maygay) (M1A/B) (set 1) | MAME |
| Under Siege (Maygay) (M1A/B) (set 2) | MAME |
| Under Siege (Maygay) (M1A/B) (set 3) | MAME |
| Under Siege (Maygay) (M1A/B) (set 4) | MAME |
| Under the Ice (1987)(Lyric)[cr Law] | Atari ST |
| Under the Skin (Europe) (En,Fr,De,Es,It) | PS2 |
| UnderCover AD 2025 Kei (Japan) | DC |
| Undercover Cops (Japan) | MAME |
| Undercover Cops (Japan) | SNES |
| Undercover Cops (US) | MAME |
| Undercover Cops (World) | MAME |
| Undercover Cops - Alpha Renewal Version | MAME |
| Undercover Cops Gaiden - Hakaishin Garumaa (Japan) | GB |
| Underground (19xx)(Skorpyo)(Sp) | ZX Spectrum Z80 |
| Underground (19xx)(Skorpyo)(Sp) | ZX Spectrum (TAP) |
| Underground Adventure (19xx)(-)[h TSTH][bootfile] [SSD] | BBC Micro |
| Underground Pool (U)(Legacy) | NDS |
| Undersea Adventures (1993)(Knowledgeware) | DOS |
| Underwater Attack (U)(SQUiRE) | NDS |
| Underworld - The Eternal War (Europe) | PS2 |
| Underworld - The Eternal War (Europe) (En,Fr,De,Es,It) | PS2 |
| Underworld II, The (1984)(G.F.)[k-file] | Atari 800 |
| Underworld, The (19xx)(-) | Atari 800 |
| Underwurlde (1984)(Ultimate) | ZX Spectrum Z80 |
| Underwurlde (1984)(Ultimate)[a2] | ZX Spectrum Z80 |
| Underwurlde (1984)(Ultimate)[a3] | ZX Spectrum Z80 |
| Underwurlde (1984)(Ultimate)[a] | ZX Spectrum Z80 |
| Underwurlde (E) | C64 Tapes |
| Une Affaire en Or (F) (1985) | CPC |
| Unfabulous (U)(Rising Sun) | GBA |
| Unholy War Demo [U] [SLUS-90030] | PS1 Demos |
| Unholy War, The (USA) | PSX2PSP |
| Unholy War, The [NTSC-U] | PSX |
| UniWar S | MAME |
| UniWar S (bootleg) | MAME |
| Unibox (Union) (MPU4, set 1) | MAME |
| Unibox (Union) (MPU4, set 2) | MAME |
| Unicorn Dreaming (0100791V, NSW/ACT) | MAME |
| Unicorn Dreaming (0100813V, NSW/ACT) | MAME |
| Unicorn Dreaming (0101228V, New Zealand) | MAME |
| Unicorn Horn | Atari 800 |
| Unicum (1988)(CSP)(De)[k-file] | Atari 800 |
| Unicum 2 | Atari 800 |
| Uninvited | Amiga |
| Uninvited (UE) | C64 PP |
| Uninvited (USA) | NES |
| Uninvited, The (1987)(Icom Simulations)[cr Delta Force] | Atari ST |
| Union Jackpot (JPM) (SYSTEM5, set 1) | MAME |
| Union Jackpot (JPM) (SYSTEM5, set 2) | MAME |
| Union Jackpot (JPM) (SYSTEM5, set 3) | MAME |
| Unior | MAME |
| Unique (Union) (MPU4, set 1) | MAME |
| Unique (Union) (MPU4, set 2) | MAME |
| Uniracers (USA) | SNES |
| Unirally (Europe) | SNES |
| Unison - Rebels of Rhythm & Dance (USA) | PS2 |
| Unistar 200 Terminal | MAME |
| United (1984)(CCS) | ZX Spectrum Z80 |
| United (1984)(CCS)[a] | ZX Spectrum Z80 |
| United States Adventure (1984)(First Star Software)[Basic] | Atari 800 |
| United States Adventure (19xx)(First Star) | Apple2 |
| Unitrax (1987)(Domark) | ZX Spectrum Z80 |
| Unitrax (1987)(Domark)[a2] | ZX Spectrum Z80 |
| Unitrax (1987)(Domark)[a] | ZX Spectrum Z80 |
| Unitrax (UK) (1987) | CPC |
| Unitron 1024 | MAME |
| Unitron AP II (in Brazilian Portuguese) | MAME |
| Unitron AP II (in English) | MAME |
| Unitron AP II+ (Teclado Inteligente) | MAME |
| Universal Chaos (AKA Targ) (1989) (Telegames) (7062 A305) | 2600 |
| Universal Hero (1987)(Mastertronic) | Atari 800 |
| Universal Hero (19xx)(Mastertronic) | ZX Spectrum Z80 |
| Universal Military Simulator 2, The - Nations at War (1991)(Intergalactic Development) | Atari ST |
| Universal Military Simulator 2, The - Nations at War (1991)(Intergalactic Development)(Disk 1 of 2)(Program)[cr Hotline] | Atari ST |
| Universal Military Simulator 2, The - Nations at War (1991)(Intergalactic Development)(Disk 2 of 2)(Map)[cr Hotline] | Atari ST |
