Armoured Patrol by Adventure International

Documentation.

A 3-D tank simulation and the controls are as follows:
  Restart Game             <SHIFT>+<BREAK>
  Fire Canon               <SPACE>
  Slow right turn:         A or "." key
  Fast                     A and "." key
  Slow left turn           Z or ";"
  Fast                     Z and ";"
  Move forward             A and ";"
  Move backward            Z and "."

There are enemy tanks and enemy robots.

Note the indicator on screen that gives you an idea of which way to turn to find the enemy.

They can shoot from behind you.

