As well as Fire Emblem 4, which I'm posting about in the Summer Games Challenge thread, today I started up Crystal Warriors for the Game Gear. It's a very simple SRPG - the plot is super basic and the game mechanics are also simple. You have a party of up to 9 heroes, and each chapter you must rout the enemies on the battlefield or seize their castle to win. You definitely want to rout enemies though because exp and money is limited and you'll want lots of it.
The game has permadeath, so you'll take things carefully, but it's not as speedy as something like Fire Emblem - it normally takes several rounds of pummeling enemies to kill them and so it's more of a brawl.
The game has an elemental system - fire units beat wind, wind beats water and water beats fire. Earth units are neutral to everything. Your main character plus all healers and mages are earth type, so it's just melee fighters who worry about elements really.
You can fight monsters on the map and catch them, and they can be used to sub in during battle. This is useful for switching in a better element monster if you're attacked by your weakness, or allowing an expendable monster to take a hit for you if you're close to dying.
Between levels you go to a town where you can buy weapons or magic, and sometimes recruit characters - but they're quite pricy, so actually you have to be quite thoughtful with your money as you can't afford everything.
It's decent enough so far, if a little low budget feeling.