For me, it's the rhythm of it all. You fight wave after wave of peons, trying to eliminate as many of them as possible in a single combo string, then you use the meter you build up from doing that to go after another wave of them or an enemy officer with an asskick special attack. Officers and commanders drop items (which sometimes give a permanent stat-up). When you get used to the game, you stop focusing on the small encounters and start thinking about the direction the battle is going, your overall objectives, what order to attack officers in, etc. Capturing bases eventually turns the map's red dots to blue, which is satisfying. Its like tidying up the map. In and between battles you also think about how you want to build your character (in the games that have stat trees) and what to do in order to get the next good weapon (which allows longer combo strings).
