Mercenary: Escape from Targ is a sci-fi action-adventure game designed by Paul Woakes and released by his company, Novagen Software, initially for Atari 8-bit in 1986. It was ported to several 8-bit and 16-bit platforms in 1986 and 1987.
The Commodore 64 version was probably the most successful, and it's considered one of the best titles ever created for the C64.
Mercenary is a game of exploration with an environment entirely rendered in 3D. Despite the hardware limitation, the programmer could create a vast, smoothly animated world using wireframe vector graphics. That's why some reviewers compared Mercenary with Elite, although they are different games.
The game is nonlinear; you can explore freely and perform tasks in any order, solving puzzles and collecting money to escape the planet Targ.
Mercenary was followed by two sequels, Mercenary II and III, released for Amiga and Atari ST. The graphics might seem a bit outdated, but this game created by Paul Woakes (who passed away in 2017) is a legend. You have to try it.