Operation Flashpoint takes place in the 1980's. Player must fight soviet forces on 3 large 100km islands as an American NATO soldier. Man vehicles such as aircraft, cars, tanks, and boats are driveable and commandable. A mission editor and other tools are also available or already built into the game itself.
this is a 1998 screenshot iirc
The best engine for such sims is 'Voxel Space'! Look into the legendary 'Delta Force' I and II!
Instead of developing and evolving that line, the game-makers fell into heavy-resourced 3D graphycs that anyway cannot provide such realistic terrain surfaces and other abilities than 'Voxel Space' can!
Resulting is systematical degradation of programming art that is now the tendention all around the world.