If you're interested in this game, then you've done your homework. Monster Kingdom: Jewel Summoner isn't getting much hype or publicity, and it isn't quite a diamond in the rough, but Monster Kingdom is still a welcome morsel for the RPG-starved PSP.
Monster Kingdom obviously relies on Pokemon -style monster gathering and the battles that accompany the hobby everywhere in the universe. With a possible nine monsters in stack for each battle, there's enough opportunity to vary your elements and form tactics against bosses. Level-grinding isn't too bad here, actually, and the advantageous creatures are thankfully in the right spots at the right times. As is common with RPGs, battles pop up a tad too frequently, and the combat system is slightly unbalanced - once you form a good monster party, you can almost assure yourself victory.