| Title | Publisher | Year | Language | Documents |
|---|---|---|---|---|
| I don't remember why this game is called "Onion" | Dan Shiovitz | 1999 | English | |
| I Never Promised You a Nose Guard | Rob Noyes | 1999 | English | Solution, Map |
| Inheritance | Eric Toth | 1999 | English | Solution |
| Isla, Amante Natural | Francisco Javier Peinado |
1999 | Spanish |