The Infantry and tanks had no real host game, and were just military units that appeared on several of Nintendo's war games (Nintendo's first War game was Famicom Wars).
Super Smash Bros. series
In Super Smash Bros. Brawl, They were an Assist trophy, and item which spawned out characters from various Nintendo games. While some characters were upgraded to fit the animation, The Infantry and Tanks were kept pixelated.
The following is the Assist Trophies' trophy description in Brawl:
Units first introduced in Famicom Wars, where they fight battles against enemy forces. Infantry are the least expensive to deploy of all units. They're not to strong, but they move well and can capture property. There are two tank types, Tank A, which is expensive but has good mobility and firepower, and Tank B, which is cheaper but can change battles with sheer numbers