1993.
Noughts and Crosses reminds me a lot of Omamoku. There's something quiet, unobtrusive about both of these games, they both have huge playing fieldsand they both are from Finland.
Pentti Moilanen wrote one more game, Graditor, an arcade space shooter with exact physics. The two games have very little in common, except that they both use virtual screens multiple times the size of the physical one.