Add extra helicopter additions for better gameplay.
For instance:
Proximity sensors that detect if you're too close to an object or the ground.
Physical screens (or just analog circles) for altitude, speed, and a working gyroscope.
An actual working screen for aiming the gun in the Apache instead of the confusing head controls.
Different armaments and loadouts randomized every match for the Apache.
And maybe some other cool tweaks and upgrades.
This in my opinion (from past gameplay) will vastly improve gameplay without twisting the core idea of how helicopters are used.