Pocket King

Original Title
Game Boy/
Official Website
Pocket King is a follow up to Namco's 1988 Famicom strategy title King of Kings, and shares many similarities with its predecessor. The basics of the game are to use your leader to summon troops onto the battlefield and fulfill the mission requirements for that stage. This will generally be "Defeat all enemies!" but variants such as "Take over all the other towns" or "Defeat the boss in X turns" also exist.
Troops cost MP to summon (but nothing to maintain), with the exact amount depending on the unit in question. MP is replenished each turn; each town captured increases the amount gained and any unused MP is carried over. Troops are summoned individually but can be merged together into groups of up to three – these can be any combination of class you have at your disposal. Once merged however the lineup cannot be altered unless one of them dies.
The towns dotted about the map don't just act as MP boosters, they can also contain events and units stationed at them at the end of a turn will have their HP replenished.
While your troops are largely nameless entities summoned at your convenience any that survive the battle can be stored and summoned in the next map with their stats intact. These troops have a lower MP cost than freshly created ones, the disadvantage being that while they may be tougher they might not be appropriate for the enemies at hand.
Units not only level up, but can also evolve. This evolution occurs every tenth level, and special units can be created using certain items or by having units with their stats skewed a particular way (e.g. A thief with a movement stat of over 7 will become a ninja, otherwise it will become an assassin).
In addition to the single player campaign mode the game also supports multiplayer skirmishes either over a link cable or with two people sharing the same GB. There are fourteen maps to choose from with a variety of terrain, none of these require unlocking beforehand. This mode can also be played against a CPU opponent if preferred.
Other non-battle features are a unit list (all 159 of them) available from the main menu and the ability to trade troops over link cable to another Pocket King player.