This would be better if it wasn't F2P - the focus on micro-transactions distorts the game a bit, making it hard for free users to play more than an hour or two at a stretch.

There are normal battles, which resemble a turn based Age of Empires II HD, except that you are limited to the tanks and infantry that you start with. This makes repair and healing units incredibly important.

Some of the vehicles are cool - like the Wheel of Doom that does 360 degree area damage. Others don't quite live up to the strengths their descriptions seem to portray. When fighting AI, it doesn't seem to use infantry much, and infantry seem to be pretty weak against any type of foe. (Including opponents that are supposedly good against armor)

There are also Smuggling runs, which involve tying up a bunch of your units for several hours - and if your convoy is attacked during the run you have to use the units you committed to fend off the raiders. If you fail to do so you lose all the units. (Except the Heros, which are returned to you 'wounded' and take time and gold to repair)

Upgrading units, researching new technologies, etc all take place outside the battles, unlike AOE2. Your money, resources, and research are persistent so you can continually upgrade your army.

Conclusion
Overall I enjoy the actual battles, but wish the units were a bit more balanced. I don't like smuggling tying up my units for hours, and my play being limited by 'Energy'. The unit micromanagement outside of the game pulls me out of the experience a bit, and I don't like having to commit to using specific units before I even know what the enemy is fielding.