Let's talk about what King's Bounty is. Heroes of Might & Magic is the easiest touchstone - a fantasy world which you roam around from a fairly birds-eye perspective, being sucked into turn-based strategic battles whenever you encounter an enemy. Whilst the battles are ostensibly Final Fantasy-esque, with two opposing sides taking turns to biff each other with wild abilities, the difference is that you're pitching armies against each other.
The Platinum Edition brings together Legend, Armored Princess, Orcs on the March and Crossworlds all into one amazing package along with a simple game editor that allows you to go off and do your own thing. Assuming you get through this immense amount of game.
If you have read about King's Bounty but as yet not taken the plunge then this is the perfect collection of RPG loveliness!