Novagen‘s classic 3D exploration game Mercenary was first released in 1985.
As a free-form kind of flying/walking game, Mercenary is fun to play and grab, because you can fly/walk/stand and orient yourself from pretty much any angle you desire. Like a photographer. And take grabs.
The puzzles were always a little too obscure for my tastes, but flying around is still great fun. The control system – using the keys 1 through to 9 for different speeds, and space for stop – help make it easy to zip around and check things out.
Mercenary might be a little bit basic by today’s standards, but it’s still great fun to load up and fly around, find objects, steal vehicles and ships, drive cars, and shoot the landscape.
Heck, if you want to play it seriously too, it’s great for just that.
More: Mercenary on Wikipedia