The terrain effects do look good in the 3D mode. The graphic quality is generally good, but has a certain dated feel. Gunfire can be seen by red tracer fire, artillery shells can be seen raining down, planes scoot overhead, trucks nip around at breakneck speed. Damaged units smoke and burn when destroyed, albeit in a garish shade of red. The game music is a jingle which you soon want to turn off, or at least turn right down - it's more irritating than inspiring.
Planes splutter overhead.
Birds tweet in the trees in woodlands. The AI ability is mixed. While the AI will often do remarkably good things and appear tactically gifted, by the same token it can be equally dumb, and that's annoying when the AI is often also controlling your forces for you. Enemy AI troops often don't fire at you, or walk right by without shooting. This in part explains why it is easier to do well when fighting in 3D mode than it is to let your fights be resolved at the tactical level.