The thing you need to know about State of War is that there was a first game released around 2001 that featured exactly the same graphics and gameplay, so basically, even 3 years later, Warmonger, feels more like a bland expansion pack, rather than a new game itself.
What was great about the first edition is now mediocre, like graphics and gameplay and what was bad, remains sadly bad.
Both in the first edition and in Warmonger you need to drive rebels away from your country. Every level you are presented with a map. The map contains different types of buildings that you either control already, are controlled by the enemy, or remain neutral. These buildings can be factories, to produce tanks, gold digs, to produce credits (which you can use to buy defense structures), satellites that produce air craft, windmills that speed the unit production, research labs to upgrade tanks and that's pretty much it. In order to control them, you must destroy them, and then suddenly they rise again but with your color, which is kind of awkward. Every scenario goal relies on destroying the most important building in the map - the headquarters. The headquarters are the strongest building in the game and its usually the most guarded. Both you and the enemy have headquarters and there it's automatically produced the most important air unit in the game - the "advancer". The "advancer" can repair buildings and destroy them, as well as upgrade them. For instance, some gold buildings have 3 levels of production and you usually start at level 1. The "advancer" can upgrade the building to level 2 or 3 to increase production speed. The "advancer" isn't affected by ground units, except for one of the anti-aircraft tanks and one of the missile turrets. However, some buildings (mostly the headquarters) come with satellite protection, meaning if you try to damage that building with your "advancer" it will instantly kill it.
About the scenarios themselves, some of them are just insanely hard. Either because you don't have your "advancer" (don't know why that happens) or because the enemy's "advancer" is out there insanely fast capturing your buildings and destroying your turrets. Sometimes because you are under attack by all sides of the map, which makes it hard for turret placement, considering you have limited credits.
The graphics are exactly the same as they were in 2002 and are tied to a 1024x768 resolution. You can check the screenshots I included for a comparison between the two games.
The game still remains very difficult and frustrating and the scenario goals are pretty much the same.
Considering the previous installment, State of War, I consider Warmonger to be below average.