| 22683 | Underground | ZX-Spectrum 128K | English |
| 13325 | Underground Adventure | ZX-Spectrum 48K | English |
| 40403 | Underline | ZX-Spectrum 48K | English |
| 40753 | Understanding Angles | ZX81 16K | English |
| 2001432 | Understanding Artificial Intelligence | - | English |
| 2000896 | Understanding C | - | English |
| 2000398 | Understanding Computer Graphics | - | English |
| 2001430 | Understanding Computer Science | - | English |
| 2001429 | Understanding Digital Troubleshooting | - | English |
| 13270 | Understanding Evolution | ZX-Spectrum 48K | English |
| 2001431 | Understanding Microprocessors | - | English |
| 2000400 | Understanding Your Spectrum | - | English |
| 2000401 | Understanding Your ZX81 ROM | - | English |
| 25990 | Underworld | ZX-Spectrum 48K | English |
| 10369 | Underworld - The Village | ZX-Spectrum 48K | English |
| 43288 | Underworld Escape | ZX-Spectrum 48K | English |
| 9446 | Underwurlde | ZX-Spectrum 48K | English |
| 22754 | Unerase | ZX-Spectrum 48K | English |
| 22767 | Unerase (+3) | ZX-Spectrum 128 +3 | English |
| 22214 | Unfrag | ZX-Spectrum 128 +3 | English |