History:

The RTV-A-2 Hiroc (high-altitude rocket) was a product of the United States' first effort to develop an intercontinental ballistic missile (ICBM). The project was named MX-774. The project was canceled in 1947, but leftover funds were used to build and launch three of the planned 10 research vehicles designated RTV-A-2. The design included several innovations; the gimbaled thrust chambers provided guidance control, the internal gas pressure was used to support the airframe and the nose cap was separable. All of these concepts were later used on the Atlas missile and the first two on the Viking rocket. Also developed as part of MX-774 was the Azusa guidance system which was not used on the Hiroc missile but did contribute to the Atlas missile as well as many other early guided missiles launched from Cape Canveral.
Wikipedia:cited

How to use:

throttle up and press ag1 and ag2 at the same time, then use trim and yaw for maneuvering, ag3 and VTOL for hyperjet engine

Other features:

a lot of explosives
smoke trail