At E3 1995 it was announced that now-defunct Boss Game Studios were working on an unnamed Virtual Boy title. We were able to talk to two of the people behind the game and uncover details about it.
The game was called "3D Tank" and was a 1st person sci-fi tank sim (like the arcade classic, Battlezone). It was developed by a team of three at Boss back in 1994/1995. Hans Piwenitzky created the initial concept in form of a "15-20 second animated demo created with an early version of Autodesk 3D, complete with a floating HUD UI". Todd Downing created further concept art, but did not spend much time on the game either since it was a secondary project in his workload. "Perhaps a week of work, no longer", he said. Third was an unknown programmer, who by far spend the most time on the game.
Statements regarding how far 3D Tank had come are conflicting, though. According to Todd Downing "the game was completed but Nintendo killed the Virtual Boy platform just prior to 3D Tank's release, so it never made it out the door." Hans Piwenitzky on the other hand told us that "nothing was ever pursued for the 3D Tank title. Boss Game did have a Virtual Boy, and had plans to develop titles for the system, but they never went further." Of course, this does not come surprising if one keeps in mind that we're talking about 17 years ago here, with both having only spend a very short timespan on the project.
However, by putting together all the available bits of information, it seems that 3D Tank was in development for some months before Boss decided to "not pursue any futher development for the Virtual Boy". As Todd Downing told us, he "personally witnessed actual gameplay on the programmer's dev kit. It had a functioning UI and controls, and at least one playable level."
Unfortunately, none of the assets from the game were attainable, or even seem to have survived. "Honestly I doubt any of the finished work survived. All of our work (code and art alike) was for-hire, meaning Boss owned it all. And none of the guys who worked on the game were at Boss when they closed up shop." Downing said.
To get an idea what the game might have looked like, have a look at the following mockups of a Virtual Boy Battlezone, that were created by Defunct Games in 2002.