SDI (Strategic Defense Initiative), released in Japan for the Sega Master System, is likely a game inspired by the real-world Strategic Defense Initiative program. The title suggests a strategy or defense-oriented game, possibly involving resource management, strategic placement, and wave-based defense against incoming threats.  Published by Sega, its gameplay specifics would benefit from further research into gameplay videos or reviews from its time of release.

SDI (Japan)

Schtroumpfs Autour du Monde, Les (Europe) (En,Fr,De,Es)