Last Remnant?
 

I found this game-

http://www.youtube.com/watch?v=ADQ09Jog3Ec

is it as good as King's Bounty(depth of tactics, spells and creatures, character development and exploration)?

I tried playing it, didn't like it due to manga style and some other things, but it's interesting and worth trying. It seemed to me more like a Final Fantasy game.

I don't know what Final Fantasy is(if it's not on PC I don't care), so can you answer regarding those things and their quality I put in parenthesis...

Last Remnant is WAY deeper than King's Bounty (no offense to the latter) in every one of those respects except perhaps depth of strategy. There is literally so much that people pretty much need to study its wiki just to not get lost. If you only play PC games, Last Remnant is not a type of game you've played so it would be impossible to explain it to you.

Yeag is jprg style as i see, tough FF was in PC. 7 and 8 for sure

I don't know how I got addicted to turn based games, I usually just played Dawn of War 1,2