Silent Debuggers is a first-person shooter video game developed by Data East. The game was originally released in 1991 for the TurboGrafx-16 console. It was re-released on the Virtual Console in Japan on June 26, 2007, in North America on July 16, 2007 and in Europe and Australia on July 20, 2007.
Gameplay
Players explore a large cargo station in search of treasure which then accidentally triggered the self destruct sequence. The player must progress from level to level, killing every monster in order to advance. On the lowest level is a computer that must be "debugged" in order to stop a self-destruct sequence. The player is assisted by a fellow debugger named Leon who provides information and weapon and is also your buddy.. The game featured a minimal ability to look up and down. Selecting a harder difficulty generated a blob-like monster that moved on the ceiling.
Source: Wikipedia, "Silent Debuggers", available under the CC-BY-SA License.